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1

Descriptive study of an outbreak of equine sarcoid in a population of Cape mountain zebra (Equus zebra zebra in the Gariep Nature Reserve  

Directory of Open Access Journals (Sweden)

Full Text Available An outbreak of equine sarcoid occurred in a population of Cape mountain zebra (Equus zebra zebra at the Gariep Nature Reserve located in the southern Free State Province of South Africa in 1996. The course of the outbreak during 1996 to 2003 is described. During this period the average population size was 69 animals. Initially (1996 all affected animals were removed from the population. New cases continued to manifest and the incidence varied between 4.6% and 17.6 %. Prevalence reached 24.7% in 2002. No sexual predilection was noticed in the 39 recorded cases. Of the affected individuals, 64 % had a single lesion and no animal had more than 4 lesions. In males, the majority of lesions occurred in the inguinal area (55.17 %, whereas in females they mostly occurred on the head and neck (41.38 %. Lesions can increase 260 % in size annually and may impede movement.

P.N. Thompson

2012-06-01

2

Parasite-mediated selection drives an immunogenetic trade-off in plains zebras (Equus quagga).  

Science.gov (United States)

Pathogen evasion of the host immune system is a key force driving extreme polymorphism in genes of the major histocompatibility complex (MHC). Although this gene family is well characterized in structure and function, there is still much debate surrounding the mechanisms by which MHC diversity is selectively maintained. Many studies have investigated relationships between MHC variation and specific pathogens, and have found mixed support for and against the hypotheses of heterozygote advantage, frequency-dependent or fluctuating selection. Few, however, have focused on the selective effects of multiple parasite types on host immunogenetic patterns. Here, we examined relationships between variation in the equine MHC gene, ELA-DRA, and both gastrointestinal (GI) and ectoparasitism in plains zebras (Equus quagga). Specific alleles present at opposing population frequencies had antagonistic effects, with rare alleles associated with increased GI parasitism and common alleles with increased tick burdens. These results support a frequency-dependent mechanism, but are also consistent with fluctuating selection. Maladaptive GI parasite 'susceptibility alleles' were reduced in frequency, suggesting that these parasites may play a greater selective role at this locus. Heterozygote advantage, in terms of allele mutational divergence, also predicted decreased GI parasite burden in genotypes with a common allele. We conclude that an immunogenetic trade-off affects resistance/susceptibility to parasites in this system. Because GI and ectoparasites do not directly interact within hosts, our results uniquely show that antagonistic parasite interactions can be indirectly modulated through the host immune system. This study highlights the importance of investigating the role of multiple parasites in shaping patterns of host immunogenetic variation. PMID:24718761

Kamath, Pauline L; Turner, Wendy C; Küsters, Martina; Getz, Wayne M

2014-05-22

3

Putative clinical piroplasmosis in a Burchell's zebra (Equus quagga burchelli) : clinical communication  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 10-year-old tame zebra gelding was presented after suffering from lethargy, nervousness, reported anaemia and icterus as well as a decreased appetite. These symptoms were seen over some months, with changing severity. The animal was immobilised, treated, and blood specimens were submitted for haematology and biochemistry. This report describes molecular characterisation of Theileria equi recovered from this animal, as well as the clinical findings, treatment and historical relevance of piro...

Collins, N. E.; Penzhorn, B. L.; Bhoora, R.; Lampen, F.

2012-01-01

4

Stop the Zebra Mussel!  

Science.gov (United States)

A data analysis activity for assessing zebra mussel invasion risk in Virginia. Site includes background information on the zebra mussel, including methods of relocation, teacher guide, a list of additional resources, and a detailed classroom activity. Activity covers zebra mussel biology, optimal habitat characteristics, environmental impacts, action plans, and follow up activities.

Clark, Vicki P.; Miller, Thomas J.

2010-11-15

5

Invasion of the zebra mussel  

Science.gov (United States)

Zebra mussels were brought to North America in the ballast water of ships. Since 1988, the zebra mussels have pushed native freshwater mussels to near-extinction. The zebra mussel invasion is a great example of time delays.

Katie Hale (CSUF;Biological Sciences)

2007-07-08

6

Zebra Finch Song Archive  

Science.gov (United States)

The Zebra Finch Song Archive was developed by Biology Professor Heather Williams of Williams College as an informational web resource. The archive currently contains songs and sonograms for 83 male zebra finches that are all descendants from a single pair. Songs can be accessed through a tabular form titled Birds and Clutches or through a well-designed Family Tree. For site visitors that would like more background about the zebra finch (including its song and brain), see the Bird Songs and Bird Brains section.

7

Observing the Zebra Finch.  

Science.gov (United States)

Presents natural history information on the zebra finch (Taeniopygia castanotis) for the biology teacher. Includes a section on care of the birds in the classroom and a method for constructing an inexpensive cage. (SA)

Waters, Charles

1979-01-01

8

Shedding of Clostridium difficile PCR ribotype 078 by zoo animals, and report of an unstable metronidazole-resistant isolate from a zebra foal (Equus quagga burchellii).  

Science.gov (United States)

Clostridium difficile is an emerging and potentially zoonotic pathogen, but its prevalence in most animal species, including exhibition animals, is currently unknown. In this study we assessed the prevalence of faecal shedding of C. difficile by zoo animals, and determined the ribotype, toxin profile and antimicrobial susceptibility of recovered isolates. A total of 200 samples from 40 animal species (36.5% of which came from plains zebra, Equus quagga burchellii) were analysed. C. difficile was isolated from 7 samples (3.5% of total), which came from the following animal species: chimpanzee (Pan troglodytes troglodytes), dwarf goat (Capra hircus), and Iberian ibex (Capra pyrenaica hispanica), with one positive sample each; and plains zebra, with 4 positive samples from 3 different individuals. Most recovered isolates (4/7, 57.1%) belonged to the epidemic PCR ribotype 078, produced toxins A and B, and had the genes encoding binary toxin (i.e. A(+)B(+)CDT(+) isolates). The remaining three isolates belonged to PCR ribotypes 039 (A(-)B(-)CDT(-)), 042 (A(+)B(+)CDT(-)) and 110 (A(-)B(+)CDT(-)). Regardless of their ribotype, all isolates displayed high-level resistance to the fluoroquinolones ciprofloxacin, enrofloxacin and levofloxacin. Some isolates were also resistant to meropenem and/or ertapenem. A ribotype 078 isolate recovered from a male zebra foal initially showed in vitro resistance to metronidazole (MIC ? 256 ?g/ml), but lost that trait after subculturing on non-selective media. We conclude that zoo animals belonging to different species can carry ribotype 078 and other toxigenic strains of C. difficile showing resistance to antimicrobial compounds commonly used in veterinary and/or human medicine. PMID:24467928

Álvarez-Pérez, Sergio; Blanco, José L; Martínez-Nevado, Eva; Peláez, Teresa; Harmanus, Celine; Kuijper, Ed; García, Marta E

2014-03-14

9

Advances in ZEBRA batteries  

Science.gov (United States)

ZEBRA batteries use plain salt and nickel as the raw material for their electrodes in combination with a ceramic electrolyte and a molten salt. This combination provides a battery system related specific energy of 120 Wh/kg and a specific power of 180 W/kg. With these data the battery is well designed for all types of electric vehicles and hybrid electric buses. The ZEBRA battery technology is industrialised in Switzerland where a new plant has a capacity of 2000 packs a year with expansion prepared for 30,000 packs a year.

Dustmann, Cord-H.

10

Zebra mussel monitoring  

Energy Technology Data Exchange (ETDEWEB)

In less than a decade, zebra mussels have become the latest environmental scourge to plague the North American power industry. Infestations in the Great Lakes region have already reached natural disaster proportions. The invasion shows little sign of subsiding; Michigan's inland waters are the next most likely threatened area. In the southern United States, the mussles' migration has extended about 50 miles deeper than experts had originally predicted. By the year 2000, zebra mussel monitoring and control efforts will cost business and industry $5 billion, according to the federal Aquatic Nuisance Prevention and Control Act of 1990. Estimates of more than $1 million to control mussel fouling are projected for the Great Lakes area alone. While small independent hydropower stations are not as susceptible to zebra mussles as coal or nuclear facilities, there is cause for concern. Infestations can quickly foul hydropower plant components, hampering equipment operation and reducing facility efficiency. In extreme cases, leaving the mussels unchecked can result in stoplog gate flow blockage or false water level gauge readings. Advance prevention is often an effective first-line of defense against this troublesome, rapidly spreading and extremely prolific mollusk. Mussel monitoring efforts should begin a year in advance of when zebra mussels are expected to appear in a given location. Hydropower facility components that come into contact or rely exclusively on raw water are at greatest risk, as are other external components such as embayment walls, screens, trashracks and fish ladders.

Hennagir, T.

1994-01-01

11

The zebra mussel  

International Nuclear Information System (INIS)

The aim of this article is, on the one hand, to provide information about the zebra mussel, its behavior, its effect on the ecosystem and the problems it poses for industry (especially in the CNA cooling systems) and, on the other hand, to review the strategies and technologies needed to control de mussel and to present the solution adopted by the power plant to combat the plague. (Author).

12

invasive species zebra mussels a3 poster final  

Zebra Mussels are not native to Ireland Don’t spread them! Zebra mussels have colonized Lough Erne, Lough Neagh and a few other small lakes. Help is needed to prevent them spreading to other water bodies. Zebra mussels ...

13

The function of zebra stripes.  

Science.gov (United States)

Despite over a century of interest, the function of zebra stripes has never been examined systematically. Here we match variation in striping of equid species and subspecies to geographic range overlap of environmental variables in multifactor models controlling for phylogeny to simultaneously test the five major explanations for this infamous colouration. For subspecies, there are significant associations between our proxy for tabanid biting fly annoyance and most striping measures (facial and neck stripe number, flank and rump striping, leg stripe intensity and shadow striping), and between belly stripe number and tsetse fly distribution, several of which are replicated at the species level. Conversely, there is no consistent support for camouflage, predator avoidance, heat management or social interaction hypotheses. Susceptibility to ectoparasite attack is discussed in relation to short coat hair, disease transmission and blood loss. A solution to the riddle of zebra stripes, discussed by Wallace and Darwin, is at hand. PMID:24691390

Caro, Tim; Izzo, Amanda; Reiner, Robert C; Walker, Hannah; Stankowich, Theodore

2014-01-01

14

New Concerns Emerge as Zebra Mussel Spreads.  

Science.gov (United States)

Reports on the Zebra Mussel invasion of North American inland waterways. Discusses United States Army Corps of Engineers operations that may facilitate or be affected by the spread of Zebra Mussels, the threat to native clams, chemical and mechanical control methods, natural solutions, and ongoing research. (MCO)

Walter, Martha L., Ed.

1992-01-01

15

ZEBRA battery meets USABC goals  

Science.gov (United States)

In 1990, the California Air Resources Board has established a mandate to introduce electric vehicles in order to improve air quality in Los Angeles and other capitals. The United States Advanced Battery Consortium has been formed by the big car companies, Electric Power Research Institute (EPRI) and the Department of Energy in order to establish the requirements on EV-batteries and to support battery development. The ZEBRA battery system is a candidate to power future electric vehicles. Not only because its energy density is three-fold that of lead acid batteries (50% more than NiMH) but also because of all the other EV requirements such as power density, no maintenance, summer and winter operation, safety, failure tolerance and low cost potential are fulfilled. The electrode material is plain salt and nickel in combination with a ceramic electrolyte. The cell voltage is 2.58 V and the capacity of a standard cell is 32 Ah. Some hundred cells are connected in series and parallel to form a battery with about 300 V OCV. The battery system including battery controller, main circuit-breaker and cooling system is engineered for vehicle integration and ready to be mounted in a vehicle [J. Gaub, A. van Zyl, Mercedes-Benz Electric Vehicles with ZEBRA Batteries, EVS-14, Orlando, FL, Dec. 1997]. The background of these features are described.

Dustmann, Cord-H.

16

Motion camouflage induced by zebra stripes.  

Science.gov (United States)

The functional significance of the zebra coat stripe pattern is one of the oldest questions in evolutionary biology, having troubled scientists ever since Charles Darwin and Alfred Russel Wallace first disagreed on the subject. While different theories have been put forward to address this question, the idea that the stripes act to confuse or 'dazzle' observers remains one of the most plausible. However, the specific mechanisms by which this may operate have not been investigated in detail. In this paper, we investigate how motion of the zebra's high contrast stripes creates visual effects that may act as a form of motion camouflage. We simulated a biologically motivated motion detection algorithm to analyse motion signals generated by different areas on a zebra's body during displacements of their retinal images. Our simulations demonstrate that the motion signals that these coat patterns generate could be a highly misleading source of information. We suggest that the observer's visual system is flooded with erroneous motion signals that correspond to two well-known visual illusions: (i) the wagon-wheel effect (perceived motion inversion due to spatiotemporal aliasing); and (ii) the barber-pole illusion (misperceived direction of motion due to the aperture effect), and predict that these two illusory effects act together to confuse biting insects approaching from the air, or possibly mammalian predators during the hunt, particularly when two or more zebras are observed moving together as a herd. PMID:24368147

How, Martin J; Zanker, Johannes M

2014-06-01

17

Dynamics of zebra finch and mockingbird vocalizations  

Science.gov (United States)

Along with humans, whales, and bats, three groups of birds which include songbirds (oscines) such as the Zebra Finch (Taeniopygia guttata) and Mockingbird (Mimus polyglottos) are the only creatures known to learn sounds by imitation. Numerous similarities between human and songbird vocalizations exist and, recently, it has been shown that Zebra Finch in particular possesses a gene, FoxP2, known to be involved in human language. This thesis investigates song development in Zebra Finches, as well as the temporal dynamics of song in Mockingbirds. Zebra Finches have long been the system of choice for studying vocal development, ontogeny, and complexity in birdsong. Physicists find them intriguing because the spectrally complex vocalizations of the Zebra Finch can exhibit sudden transitions to chaotic dynamics, period doubling & mode-locking phenomena. Mockingbirds, by contrast, provide an ideal system to examine the richness of an avian repertoire, since these musically versatile songbirds typically know upwards of 200 songs. To analyse birdsong data, we have developed a novel clustering algorithm that can be applied to the bird's syllables, tracing their dynamics back to the earliest stages of vocal development. To characterize birdsong we have used Fourier techniques, based upon multitaper spectral analysis, to optimally work around the constraints imposed by (Heisenberg's) time-frequency uncertainty principle. Furthermore, estimates that provide optimal compromise between frequency and temporal resolution have beautiful connections with solutions to the Helmholtz wave equation in prolate spheroidal coordinates. We have used this connection to provide firm foundation for certain heuristics used in the literature to compute associated spectral derivatives and supply a pedagogical account here in this thesis. They are of interest because spectral derivatives emphasize sudden changes in the dynamics of the underlying phenomenon, and often provide a nice way to visualize such dynamics. Our Zebra Finch data consist of continuous recordings of six tutored birds from the early, plastic stages of sound production to the development of fully crystallized mature song. Our analysis reveals that well before the Zebra Finch hears adult song, identifiably distinct clusters are observable for all birds in the same regions of feature space. (Abstract shortened by UMI.)

Cimenser, Aylin

18

CA/CPS: A Communications ZEBRA implementation using CPS  

International Nuclear Information System (INIS)

CZ/CPS is an implementation of the Communications ZEBRA distributed computing environment utilizing the CPS communications protocol. CZ/CPS is intended for parallelization of high energy physics application programs using the CERN Program Library memory and data structure management features. CZ/CPS provides transparent communication of ZEBRA data structures among cooperative processes using standard interfaces for ZEBRA I/O. Examples of usage in a CPS HBOOK4 and GEANT3 application are provided

19

Zebra finch cell lines from naturally occurring tumors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The zebra finch (Taeniopygia guttata) has been intensively studied in many research fields including neuroscience, behavioral neurobiology, and evolution of the genome. Although numerous molecular and genomic resources are available for this model species, immortalized cell lines have been lacking. We have established two zebra finch cell lines derived from spontaneous tumors. ZFTMA is a tetraploid female cell line and G266 as a diploid male cell line. These first zebra finch cell lines shoul...

Itoh, Yuichiro; Arnold, Arthur P.

2011-01-01

20

Invasion of the Zebra Mussels: A Mock Trial Activity  

Science.gov (United States)

In this activity, students learn about the important topic of invasive species, specifically Zebra Mussels. Students role-play different characters in a real-life situation: the trial of the Zebra Mussel for unlawful disruption of the Great Lakes ecosystem. Students will also learn about jurisprudential inquiry by examining the trial process. This…

Beck, Judy A.; Czerniak, Charlene M.

2005-01-01

 
 
 
 
21

Molecular ecology of zebra mussel invasions.  

Science.gov (United States)

The invasion of the zebra mussel, Dreissena polymorpha, into North American waters has resulted in profound ecological disturbances and large monetary losses. This study examined the invasion history and patterns of genetic diversity among endemic and invading populations of zebra mussels using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. Patterns of haplotype frequency indicate that all invasive populations of zebra mussels from North America and Europe originated from the Ponto-Caspian Sea region. The distribution of haplotypes was consistent with invasive populations arising from the Black Sea drainage, but could not exclude the possibility of an origin from the Caspian Sea drainage. Similar haplotype frequencies among North American populations of D. polymorpha suggest colonization by a single founding population. There was no evidence of invasive populations arising from tectonic lakes in Turkey, while lakes in Greece and Macedonia contained only Dreissena stankovici. Populations in Turkey might be members of a sibling species complex of D. polymorpha. Ponto-Caspian derived populations of D. polymorpha (theta = 0.0011) and Dreissena bugensis (one haplotype) exhibited low levels of genetic diversity at the COI gene, perhaps as a result of repeated population bottlenecks. In contrast, geographically isolated tectonic lake populations exhibited relatively high levels of genetic diversity (theta = 0.0032 to 0.0134). It is possible that the fluctuating environment of the Ponto-Caspian basin facilitated the colonizing habit of invasive populations of D. polymorpha and D. bugensis. Our findings were concordant with the general trend of destructive freshwater invaders in the Great Lakes arising from the Ponto-Caspian Sea basin. PMID:16599964

May, Gemma E; Gelembiuk, Gregory W; Panov, Vadim E; Orlova, Marina I; Lee, Carol Eunmi

2006-04-01

22

Environmentally Safe Control of Zebra Mussel Fouling  

Energy Technology Data Exchange (ETDEWEB)

The two primary objectives of this USDOE-NETL contract were successfully achieved during the project: (1) to accelerate research on the development of the bacterium Pseudomonas fluorescens strain CL145A (Pf-CL145A) as a biocontrol agent for zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis)--two invasive freshwater bivalve species that are infesting water pipes in power plants; and (2) to identify a private-sector company that would move forward to commercialize Pf-CL145A as a substitute for the current polluting use of biocide chemicals for control of these dreissenid mussels in power plant pipes.

Daniel Molloy

2008-02-29

23

Monitoring the condition of mountain zebra habitat in the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available The study aimed at determining an appropriate sampling design for monitoring the quality of mountain zebra habitat. The parameter used for monitoring was an index of habitat suitability. The value of this index was greater than 20 in the habitat that was most favoured by the mountain zebras, whereas values below 20 were characteristic of moderate to poor habitat. It is recommended that if the index in the most favoured habitat declines to below 20, management intervention in the form of a reduction in stocking rate of large herbivores should be considered. A sample size of 20 randomly located monitoring plots should be adequate to detect a decline to below the critical level. There was considerable patchiness in the distribution of grazing pressure within plant communities, and this needs to be taken into account in the design of the monitoring programme.

P.A. Novellie

1994-09-01

24

ZEBRA2, encoding a carotenoid isomerase, is involved in photoprotection in rice.  

Science.gov (United States)

"zebra" mutants have alternating green and chlorotic crossbands on leaf blades and are widely distributed in monocotyledonous crops. Most recently, we cloned the first responsible gene from rice, ZEBRA2, which also leads to the phenotype of rice preharvest sprouting. ZEBRA2, a single-copy gene in the rice genome, encodes a carotenoid isomerase (CRTISO), the key enzyme catalyzing the conversion of cis-lycopene to all-trans lycopene. ZEBRA2 shares high identity with known CRTISOs from other species. Expression analysis via both RT-PCR and ZEBRA2-promoter-?-glucuronidase (GUS) transgenic rice indicates that ZEBRA2 is predominantly expressed in mesophyll cells of mature leaves where active photosynthesis occurs. Consistent with the alteration in agronomic traits, the zebra2 mutant exhibits decreased photosynthetic rate and chlorophyll content. Mutation of the ZEBRA2 gene results in the accumulation of all-trans-lycopene precursor, prolycopene (7Z,9Z,7'Z,9'Z tetra cis-lycopene), in dark-grown zebra2 tissues. Light-grown zebra2 mutant exhibits the characteristic "zebra" phenotype and decreased level of lutein, the xanthophyll that is essential for efficient chl triplet quenching. More severe phenotype of the zebra2 mutant under high light intensity indicates that "zebra" phenotype might be caused by photooxidative damages. We conclude that ZEBRA2 is involved in photoprotection in rice. PMID:21161331

Chai, Chenglin; Fang, Jun; Liu, Yang; Tong, Hongning; Gong, Yanqing; Wang, Yiqin; Liu, Min; Wang, Youping; Qian, Qian; Cheng, Zhukuan; Chu, Chengcai

2011-02-01

25

Complete mitochondrial genome of the Zebra bullhead shark Heterodontus zebra (Heterodontiformes: Heterodontidae).  

Science.gov (United States)

The complete mitochondrial genome of the Zebra bullhead shark Heterodontus zebra was first presented in this study. It was 16,720 bp in length, encoding 37 genes and one control region. The gene order and translate orientation were identical to most vertebrates. Overall nucleotide base composition of H. zebra mitogenome was 31.6% A; 26.8% C; 13.1% G and 28.4% T. Total 27 bp overlaps and 20 bp short intergenic spaces were found in 17 gene junctions in the genome. Two start codons (ATG and GTG) and three terminate codons (TAG, TAA and T) were found in 13 protein-coding genes. Except for tRNA-Ser2, which lost the dihydrouridine (DHU) arm and formed one simple loop, the remaining tRNAs could fold into the typical clover-leaf secondary structures. The termination-associated sequences and three short conserved blocks (CBS I-III) were identified in the control region. PMID:25023667

Chen, Xiao; Peng, Xin; Huang, Xiaolin; Xiang, Dan

2014-08-01

26

Physico-chemical, microbiological, textural and sensory attributes of matured game salami produced from springbok (Antidorcas marsupialis), gemsbok (Oryx gazella), kudu (Tragelaphus strepsiceros) and zebra (Equus burchelli) harvested in Namibia.  

Science.gov (United States)

Differences and consumer acceptability of matured salami produced from game species were evaluated. The pH of the salami differed (p 0.05) were observed among the species for a(w), shear force, gumminess or cohesiveness. Microbiological counts of the game salami differed for coliform (p 0.05) counts. The most distinctive characteristics observed by the quantitative descriptive analyses were smoky, salty, pepper and salami flavour, combined with a smoky, salami aroma. Game flavour was not perceived as a strong attribute during the sensory analyses. Gemsbok salami was strongly associated with the attribute colour as described by the male and female consumer panels. The springbok salami scored the lowest for both colour and taste. Salami produced from gemsbok, kudu and zebra were superior to springbok salami. PMID:21185658

van Schalkwyk, D L; McMillin, K W; Booyse, Mardé; Witthuhn, R C; Hoffman, L C

2011-05-01

27

ZEBRA batteries, enhanced power by doping  

Science.gov (United States)

The ZEBRA battery, based on the reaction sodium+nickel chloride?sodium chloride+nickel, is well known for its high energy density of 118 W h/kg (cell) or 87 W h/kg (battery system including battery box and all peripheral equipment). The power density was increased in a first step by implementing a clover leaf-shaped ceramic electrolyte instead of the round tube electrolyte. A further improvement of the power density was achieved by doping of the positive nickel/nickel chloride electrode with iron, resulting in constant peak power of the battery system of 170 W/kg. The mechanism of the doping is described. The doping has no adverse effect on cycle life as a life test with presently 1100 nameplate cycles shows and this test is continuing.

Böhm, H.; Beyermann, G.

28

Doppler coefficient measurements in Zebra Core 5  

International Nuclear Information System (INIS)

Measurements using a central hot loop in Zebra Core 5 are described. Results are given for the Doppler coefficients found in a number of assemblies with PuO2 and 16% PuO2/84% depleted UO2 pins, loaded with different combinations of steel, sodium or void pins. The mixed oxide results are in general about 20% more negative than was calculated using the FD2 data set, but agreement is good if the plutonium contributions in the calculations are omitted. The small positive Doppler coefficient calculated for Pu239 was not observed, and two measurements indicated instead a small negative effect. The Doppler effect in the mixed oxide systems was found to vary approximately as 1/T. The results from the empty loop and non-fissile assemblies indicate either a small negative Doppler effect in steel or alternatively the presence of an unexplained expansion effect. (author)

29

Full Genome Sequences of Zebra-Borne Equine Herpesvirus Type 1 Isolated from Zebra, Onager and Thomson's Gazelle.  

Science.gov (United States)

A strain of equine herpesvirus type 1 (EHV-1) was isolated from zebra. This strain, called "zebra-borne EHV-1", was also isolated from an onager and a gazelle in zoological gardens in U.S.A. The full genome sequences of the 3 strains were determined. They shared 99% identities with each other, while they shared 98% and 95% identities with the horse derived EHV-1 and equine herpesvirus type 9, respectively. Sequence data indicated that the EHV-1 isolated from a polar bear in Germany is one of the zebra-borne EHV-1 and not a recombinant virus. These results indicated that zebra-borne EHV-1 is a subtype of EHV-1. PMID:24920546

Guo, Xiaoqin; Izume, Satoko; Okada, Ayaka; Ohya, Kenji; Kimura, Takashi; Fukushi, Hideto

2014-10-01

30

The zebra finch neuropeptidome: prediction, detection and expression  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Among songbirds, the zebra finch (Taeniopygia guttata is an excellent model system for investigating the neural mechanisms underlying complex behaviours such as vocal communication, learning and social interactions. Neuropeptides and peptide hormones are cell-to-cell signalling molecules known to mediate similar behaviours in other animals. However, in the zebra finch, this information is limited. With the newly-released zebra finch genome as a foundation, we combined bioinformatics, mass-spectrometry (MS-enabled peptidomics and molecular techniques to identify the complete suite of neuropeptide prohormones and final peptide products and their distributions. Results Complementary bioinformatic resources were integrated to survey the zebra finch genome, identifying 70 putative prohormones. Ninety peptides derived from 24 predicted prohormones were characterized using several MS platforms; tandem MS confirmed a majority of the sequences. Most of the peptides described here were not known in the zebra finch or other avian species, although homologous prohormones exist in the chicken genome. Among the zebra finch peptides discovered were several unique vasoactive intestinal and adenylate cyclase activating polypeptide 1 peptides created by cleavage at sites previously unreported in mammalian prohormones. MS-based profiling of brain areas required for singing detected 13 peptides within one brain nucleus, HVC; in situ hybridization detected 13 of the 15 prohormone genes examined within at least one major song control nucleus. Expression mapping also identified prohormone messenger RNAs in areas associated with spatial learning and social behaviours. Based on the whole-genome analysis, 40 prohormone probes were found on a commonly used zebra finch brain microarray. Analysis of these newly annotated transcripts revealed that six prohormone probes showed altered expression after birds heard song playbacks in a paradigm of song recognition learning; we partially verify this result experimentally. Conclusions The zebra finch peptidome and prohormone complement is now characterized. Based on previous microarray results on zebra finch vocal learning and synaptic plasticity, a number of these prohormones show significant changes during learning. Interestingly, most mammalian prohormones have counterparts in the zebra finch, demonstrating that this songbird uses similar biochemical pathways for neurotransmission and hormonal regulation. These findings enhance investigation into neuropeptide-mediated mechanisms of brain function, learning and behaviour in this model.

Annangudi Suresh P

2010-04-01

31

New insights into the function of the stripes found on zebras  

Science.gov (United States)

How The Zebra Got Its Stripeshttp://news.discovery.com/animals/zebra-stripes-120209.htmlZebra Stripes Evolved to Keep Flies Awayhttp://www.ibtimes.com/articles/296757/20120210/zebra-stripes-evolved-keep-flies-away-study.htmThe Zebra's Stripes: A Personal No-Fly Zonehttp://www.npr.org/2012/02/11/146737329/the-zebras-stripes-a-personal-no-fly-zoneHowStuffWorks: Are zebras black with white stripes or white with black stripes?http://science.howstuffworks.com/environmental/life/zoology/mammals/zebra-stripes.htmZebras, Zebra Pictures, Zebra Factshttp://animals.nationalgeographic.com/animals/mammals/zebra/Natural History Notebooks: Zebrashttp://nature.ca/notebooks/english/zebra.htmThe question of why zebras have stripes has fascinated animal biologists, literary types, and others for millennia. Some used to think that the stripes were a form of camouflage, a theory criticized by Charles Darwin due to the fact that zebras prefer open savannahs, rather than heavily forested areas. A new study performed by an international team of researchers suggests that the zebra's stripes are actually an advanced form of fly repellent. Leading a team of colleagues, Dr. Gabor Horvath of Eotvos University in Budapest conducted a series of studies with horse-shaped models, some of which were painted uniformly dark, some painted uniformly white, and some with stripes of various widths. They were looking to see if horseflies would prefer a certain object, and as it turns out, the least attractive of these items were the ones with the stripes that most closely resembled those found on zebra hides. The reasons for this selection remain unclear, but Horvath has speculated that it might be due to the fact that horseflies have a difficult time seeing polarized light. As such, the horseflies might confuse the small animals, and make it difficult to see the zebras. The first link will take users to a piece on this recent discovery by Emily Sohn, writing for Discovery News. The second link leads users to another piece from last Friday's International Business Times on the subject. Moving along, the third link will whisk users away to a short radio piece from NPR's Weekend Edition about this latest experiment into the world of the zebra's stripes. The fourth link leads to a fun article from HowStuffWorks about the color of zebras. The fifth link gives interested parties the ability to browse through many fabulous photos of zebras, courtesy of National Geographic. The last link will take visitors to a wonderful site about zebras from the Canadian Museum of Nature.

Grinnell, Max

2012-02-17

32

Song Recognition in Zebra Finches: Are There Sensitive Periods for Song Memorization?  

Science.gov (United States)

Male zebra finches learn to sing songs that they hear between 25 and 65 days of age, the sensitive period for song learning. In this experiment, male and female zebra finches were exposed to zebra finch songs either before (n = 9) or during (n = 4) the sensitive period. Following song exposure, recognition memory for the songs was assessed with an…

Braaten, Richard F.

2010-01-01

33

IMPACT OF WATER PH ON ZEBRA MUSSEL MORTALITY  

International Nuclear Information System (INIS)

The experiments conducted this past quarter have suggested that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels throughout the entire range of pH values tested (7.2 to 8.6). Highest mortality was achieved at pH values characteristic of preferred zebra mussel waterbodies, i.e., hard waters with a range of 7.8 to 8.6. In all water types tested, however, ranging from very soft to very hard, considerable mussel kill was achieved (83 to 99% mean mortality), suggesting that regardless of the pH or hardness of the treated water, significant mussel kill can be achieved upon treatment with P. fluorescens strain CL0145A. These results further support the concept that this bacterium has significant potential for use as a zebra mussel control agent in power plant pipes receiving waters with a wide range of physical and chemical characteristics

34

FindZebra : a search engine for rare diseases  

DEFF Research Database (Denmark)

Background: The web has become a primary information resource about illnesses and treatments for both medical and non-medical users. Standard web search is by far the most common interface to this information. It is therefore of interest to find out how well web search engines work for diagnostic queries and what factors contribute to successes and failures. Among diseases, rare (or orphan) diseases represent an especially challenging and thus interesting class to diagnose as each is rare, diverse in symptoms and usually has scattered resources associated with it. Methods: We design an evaluation approach for web search engines for rare disease diagnosis which includes 56 real life diagnostic cases, performance measures, information resources and guidelines for customising Google Search to this task. In addition, we introduce FindZebra, a specialized (vertical) rare disease search engine. FindZebra is powered by open source search technology and uses curated freely available online medical information. Results: FindZebra outperforms Google Search in both default set-up and customised to the resources used by FindZebra. We extend FindZebra with specialized functionalities exploiting medical ontological information and UMLS medical concepts to demonstrate different ways of displaying the retrieved results to medical experts. Conclusions: Our results indicate that a specialized search engine can improve the diagnostic quality without compromising the ease of use of the currently widely popular standard web search. The proposed evaluation approach can be valuable for future development and benchmarking. The FindZebra search engine is available at http://www.findzebra.com/. © 2013 Elsevier Ireland Ltd. All rights reserved.

Dragusin, Radu; Petcu, Paula

2013-01-01

35

FindZebra: A search engine for rare diseases  

DEFF Research Database (Denmark)

Background: The web has become a primary information resource about illnesses and treatments for both medical and non-medical users. Standard web search is by far the most common interface for such information. It is therefore of interest to find out how well web search engines work for diagnostic queries and what factors contribute to successes and failures. Among diseases, rare (or orphan) diseases represent an especially challenging and thus interesting class to diagnose as each is rare, diverse in symptoms and usually has scattered resources associated with it. Methods: We use an evaluation approach for web search engines for rare disease diagnosis which includes 56 real life diagnostic cases, state-of-the-art evaluation measures, and curated information resources. In addition, we introduce FindZebra, a specialized (vertical) rare disease search engine. FindZebra is powered by open source search technology and uses curated freely available online medical information. Results: FindZebra outperformsGoogle Search in both default setup and customised to the resources used by FindZebra. We extend FindZebra with specialized functionalities exploiting medical ontological information and UMLS medical concepts to demonstrate different ways of displaying the retrieved results to medical experts. Conclusions: Our results indicate that a specialized search engine can improve the diagnostic quality without compromising the ease of use of the currently widely popular web search engines. The proposed evaluation approach can be valuable for future development and benchmarking. The FindZebra search engine is available at http://www.findzebra.com/.

Lioma, Christina Amalia; Cox, Ingemar

2013-01-01

36

IMPACT OF WATER TEMPERATURE ON ZEBRA MUSSEL MORTALITY  

Energy Technology Data Exchange (ETDEWEB)

These tests conducted this past quarter have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels at water temperatures ranging from 7 to 23 C. Percent kill will likely be somewhat lower at very low temperatures, e.g., 7 C, but even at such low temperatures high mussel kill can still be achieved (>70% kill). This is significant because the development of a zebra mussel control method that is efficacious in such a wide range of temperatures broadens its usefulness as a potential commercial product.

Daniel P. Molloy

2002-08-07

37

Activation domain requirements for disruption of Epstein-Barr virus latency by ZEBRA.  

Science.gov (United States)

Latent infection of B lymphocytes by Epstein-Barr virus (EBV) can be disrupted by expression of the EBV ZEBRA protein. ZEBRA, a transcriptional activator, initiates the EBV lytic cascade by activating viral gene expression. ZEBRA is also indispensable for viral replication and binds directly to the EBV lytic origin of replication. The studies described herein demonstrate that the activation domain. ZEBRA activation can be replaced by a heterologous acidic, proline-rich, or glutamine-rich activation domain. ZEBRA activation domain swap constructs retain ZEBRA's native abilities to activate specific EBV promoters, to disrupt EBV latency, and to stimulate replication at the EBV lytic origin. Additional work, employing sequential and internal deletions of ZEBRA's N-terminal activation domain, indicates that its separate activities are not attributable to specific subdomains but are spread throughout its N terminus and therefore cannot be inactivated by deleting localized regions. PMID:9261375

Askovi?, S; Baumann, R

1997-09-01

38

A simple index of habitat suitability for Cape mountain zebras  

Directory of Open Access Journals (Sweden)

Full Text Available An index of habitat suitability for Cape mountain zebras was calculated using two parameters: acceptability indices for different grass species, and the aerial cover of the grass species in the habitat. The index was tested by calculating its value for a range of different habitat patches and comparing this with the frequency of use of the patches by zebras. The close relationship between the index and the observed frequency of use verified that the index could be used as a guide to habitat suitability. Two methods were used to determine the frequency of use of the patches: counts of faecal pellet groups and frequency of sightings. Both methods yielded similar results but the pellet group counts were less time- consuming and expensive. It is recommended that the index of habitat suitability be used (i as a parameter for monitoring of long-term changes in habitat suitability in the Mountain Zebra National Park and (ii as a guide for selecting appropriate areas to re- introduce mountain zebras.

A. Winkle

1993-09-01

39

Heart synchronization for SPIM microscopy of living zebra fish  

Science.gov (United States)

We describe work on producing a selective plane illumination microscope for cardiac imaging in zebra fish embryos. The system has a novel synchronization system for imaging oscillating structures (e.g. the heart) and will have adaptive optics for image optimization.

Taylor, J. M.; Saunter, C. D.; Chaudhry, B.; Henderson, D. J.; Love, G. D.; Girkin, J. M.

2011-03-01

40

REGIONAL SUSCEPTIBILITY OF NORTHEAST LAKES TO ZEBRA MUSSEL INVASION  

Science.gov (United States)

The rapid spread of the exotic zebra mussel (Dreissena polymorpha) concerns aquatic resource managers in the United States and Canada. ince 1990 it has been spreading from the Great Lakes into the Northeast. he primary goal of this study is to provide lake resource managers in th...

 
 
 
 
41

The Effect of Zebra Mussels on Algal Community Structure in an Impounded River System  

Science.gov (United States)

The zebra mussel, Dreissena polymorpha, invaded the Great Lakes Region in the mid 1980's, and subsequently colonized inland lakes and coastal river systems through secondary invasions. The Muskegon River below Croton Dam was colonized by zebra mussels in 2000 following their introduction into Croton impoundment in the late 1990's. No zebra mussels were found below Croton Dam in 1999 but had increased to 25,000 m-2 by 2001. We examined the affect of zebra mussels on epilithic periphyton communities by comparing plots that were and were not colonized by zebra mussels. Chlorophyll a increased in both treatments over time but was significantly higher in control plots than in zebra mussel plots. The concentration of chlorophyll a in the control plots increased from 14 µgcm-2 to 26 µgcm-2 and the concentration in the zebra mussel plots started at 12 µgcm-2, peaked at 19 µgcm-2, and then decreased to 15 µgcm-2 over a 6 week period. In a related experiment using artificial streams, chlorophyll a increased with increasing zebra mussel density, but differences were not significant. The different trends observed between the two experiments may be explained in part by arthropod invertebrates associated with zebra mussel populations.

Trumble, A. F.; Luttenton, M.

2005-05-01

42

Colour preferences in nest-building zebra finches.  

Science.gov (United States)

Some bird species are selective in the materials they choose for nest building, preferring, for example, materials of one colour to others. However, in many cases the cause of these preferences is not clear. One of those species is the zebra finch, which exhibits strong preferences for particular colours of nest material. In an attempt to determine why these birds strongly prefer one colour of material over another, we compared the preferences of paired male zebra finches for nest material colour with their preferences for food of the same colours. We found that birds did indeed prefer particular colours of nest material (in most cases blue) but that they did not generally prefer food of one colour over the other colours. It appears, then, that a preference for one colour or another of nest material is specific to the nest-building context. This article is part of a Special Issue entitled: insert SI title. PMID:23860278

Muth, Felicity; Steele, Matthew; Healy, Susan D

2013-10-01

43

A phytosociological reconnaissance of the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available The vegetation of the Mountain Zebra National Park, situated within the Eastern Mixed Karooveld of the Republic of South Africa, was surveyed and analysed according to the Braun-Blanquet phytosociological method of sampling and synthesis. Brief discussions on the phytogeography of the Karoo and the physiography and climate of the Park are included. Three distinct major vegetation types are described floristically, physiognomically and ecologically. A vegetation map of the Park is provided.

P. T van der Walt

1980-01-01

44

Reg outcome in an alarm situation in zebra finches  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Micro-PK was explored in zebra finches (Taeniopygia guttata) to test the hypothesis of nondirectional REG randomness reduction during an alarm situation. A 15-s video clip of a crawling snake was presented to 80 participants and a REG's outcome during the presentation of the stimulus was analysed under three conditions: Bird Alone, Bird Plus Observer, and Observer Alone. One 200-bit trial was collected every quarter of a second during die presentation of the stimulus and the 5-min control per...

A?lvarez, Fernando

2011-01-01

45

Analysis of CR1 Repeats in the Zebra Finch Genome  

Directory of Open Access Journals (Sweden)

Full Text Available Most bird species have smaller genomes and fewer repeats than mammals. Chicken Repeat 1 (CR1 repeat is one of the most abundant families of repeats, ranging from ~133,000 to ~187,000 copies accounting for ~50 to ~80% of the interspersed repeats in the zebra finch and chicken genomes, respectively. CR1 repeats are believed to have arisen from the retrotransposition of a small number of master elements, which gave rise to multiple CR1 subfamilies in the chicken. In this study, we performed a global assessment of the divergence distributions, phylogenies, and consensus sequences of CR1 repeats in the zebra finch genome. We identified and validated 34 CR1 subfamilies and further analyzed the correlation between these subfamilies. We also discovered 4 novel lineage-specific CR1 subfamilies in the zebra finch when compared to the chicken genome. We built various evolutionary trees of these subfamilies and concluded that CR1 repeats may play an important role in reshaping the structure of bird genomes.

George E. Liu

2013-06-01

46

Opioid modulation of song in male zebra finches (Taenopygia guttata).  

Science.gov (United States)

Endogenous opioids are known to modulate motivated behaviors. Male zebra finches produce a highly motivated behavior (directed song) to court females and also sing in isolation (undirected song). We found that adult male zebra finches sang significantly fewer directed and undirected songs after administration of low doses (2.5 mg/kg body weight) of the general opioid antagonist naloxone, even though the order of syllables in songs was not altered. Surprisingly, high doses of naloxone (10 mg/kg body weight) dramatically decreased the production of undirected songs but had no significant effects on directed songs. There were no changes in the number of calls during directed or undirected song, movement, stereotyped behaviors including pecking and preening, feeding or drinking behaviors after naloxone administration. We also found that treating zebra finches with naloxone led to a decrease in tonality (goodness of pitch), frequency and amplitude modulation and an increase in the length of intersyllable intervals. Our results suggest that the opioid system can differentially modulate directed and undirected song as well as the acoustic characteristics of birdsong, perhaps by acting on different components of the song control system. PMID:20015456

Khurshid, Nazia; Jayaprakash, Navin; Hameed, L Shahul; Mohanasundaram, Sivaraj; Iyengar, Soumya

2010-04-01

47

Parasites and diseases of Cape Mountain zebra, black wildebeest, mountain reedbuck and blesbok in the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available

The results of a special survey are supplemented inthis report with a review of all other applicable information onthe diseases and parasites of Cape mountain zebra, black wildebeest, mountain reedbuck and blesbok in the Mountain ZebraNational Park. The possible significance of some of these infections is discussed and various suggestions are made which aim atthe continued and successful preservation of the Cape mountainzebra and other species in this National Park.

B.L. Penzhorn

1973-07-01

48

Zebra mussel filtration and its potential uses in industrial water treatment.  

Science.gov (United States)

The zebra mussel (Dreissena polymorpha) is a notorious freshwater biofouling pest, and populations of the species can alter aquatic environments through their substantial filtration capabilities. Despite the ecological importance of zebra mussel filtration, many predictions of their large-scale effects on ecosystems rely on extrapolations from filtration rates obtained in static laboratory experiments, not accounting for natural mussel densities, boundary layer effects, flow rates or elevated algal concentrations. This study used large-scale industrial flume trials to investigate the influence of these factors on zebra mussel filtration and proposes some novel industrial applications of these findings. The flume trials revealed some of the highest zebra mussel clearance rates found to date, up to 574+/-20mlh(-1)g(-1) of wet tissue mass. Under low algal concentrations, chlorophyll a removal by zebra mussels was not proportional to mussel density, indicating that field rates of zebra mussel grazing may be much lower than previous studies have predicted. Increasing ambient velocities up to 100mls(-1) ( approximately 4cms(-1)) led to increased clearance rates by zebra mussels, possibly due to the replenishment of locally depleted resources, but higher velocities of 300mls(-1) (12cms(-1)) did not lead to further significant increases in clearance rate. When additional algal cultures were dosed into the flumes, chlorophyll a removal increased approximately logarithmically with zebra mussel density and there were no differences in the clearance of three different species of alga: Ankyra judayi, Pandorina morum and Cyclotella meneghinia. Some novel industrial uses of these zebra mussel filtration studies are proposed, such as: (1) helping to inform models that predict the large-scale grazing effects of the mussels, (2) allowing estimates of zebra mussel densities in industrial pipelines, and (3) constructing large-scale biofilters for use in water clarification. PMID:17996272

Elliott, Paul; Aldridge, David C; Moggridge, Geoff D

2008-03-01

49

Digital gene expression analysis of the zebra finch genome  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In order to understand patterns of adaptation and molecular evolution it is important to quantify both variation in gene expression and nucleotide sequence divergence. Gene expression profiling in non-model organisms has recently been facilitated by the advent of massively parallel sequencing technology. Here we investigate tissue specific gene expression patterns in the zebra finch (Taeniopygia guttata with special emphasis on the genes of the major histocompatibility complex (MHC. Results Almost 2 million 454-sequencing reads from cDNA of six different tissues were assembled and analysed. A total of 11,793 zebra finch transcripts were represented in this EST data, indicating a transcriptome coverage of about 65%. There was a positive correlation between the tissue specificity of gene expression and non-synonymous to synonymous nucleotide substitution ratio of genes, suggesting that genes with a specialised function are evolving at a higher rate (or with less constraint than genes with a more general function. In line with this, there was also a negative correlation between overall expression levels and expression specificity of contigs. We found evidence for expression of 10 different genes related to the MHC. MHC genes showed relatively tissue specific expression levels and were in general primarily expressed in spleen. Several MHC genes, including MHC class I also showed expression in brain. Furthermore, for all genes with highest levels of expression in spleen there was an overrepresentation of several gene ontology terms related to immune function. Conclusions Our study highlights the usefulness of next-generation sequence data for quantifying gene expression in the genome as a whole as well as in specific candidate genes. Overall, the data show predicted patterns of gene expression profiles and molecular evolution in the zebra finch genome. Expression of MHC genes in particular, corresponds well with expression patterns in other vertebrates.

Burke Terry

2010-04-01

50

Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens  

Energy Technology Data Exchange (ETDEWEB)

The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

Daniel P. Molloy

2004-02-24

51

Diet quality and resource allocation in the zebra finch.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated the effect of diet quality on resource allocation in zebra finches (Taeniopygia guttata) by providing females with a high-quality (HQ) or low-quality (LQ) diet for six weeks prior to pairing, and continuing these diets during egg laying and chick rearing. Diet treatments were then reversed and the experiment repeated. When females laid on the HQ diet, egg mass increased with laying order, but the reverse was true on the LQ diet. Females laid significantly more male eggs on the...

Rutstein, A. N.; Slater, P. J. B.; Graves, J. A.

2004-01-01

52

Food habits of diving ducks in the Great Lakes after the zebra mussel invasion  

Science.gov (United States)

Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

Custer, C.M.; Custer, T.W.

1996-01-01

53

Economic impacts of zebra mussels on drinking water treatment and electric power generation facilities.  

Science.gov (United States)

Invasions of nonnative species such as zebra mussels can have both ecological and economic consequences. The economic impacts of zebra mussels have not been examined in detail since the mid-1990s. The purpose of this study was to quantify the annual and cumulative economic impact of zebra mussels on surface water-dependent drinking water treatment and electric power generation facilities (where previous research indicated the greatest impacts). The study time frame was from the first full year after discovery in North America (Lake St. Clair, 1989) to the present (2004); the study area was throughout the mussels' North American range. A mail survey resulted in a response rate of 31% for electric power companies and 41% for drinking water treatment plants. Telephone interviews with a sample of nonrespondents assessed nonresponse bias; only one difference was found and adjusted for. Over one-third (37%) of surveyed facilities reported finding zebra mussels in the facility and almost half (45%) have initiated preventive measures to prevent zebra mussels from entering the facility operations. Almost all surveyed facilities (91%) with zebra mussels have used control or mitigation alternatives to remove or control zebra mussels. We estimated that 36% of surveyed facilities experienced an economic impact. Expanding the sample to the population of the study area, we estimated 267 million dollars (BCa 95% CI = 161 million dollars - 467 million dollars) in total economic costs for electric generation and water treatment facilities through late 2004, since 1989. Annual costs were greater (44,000 dollars/facility) during the early years of zebra mussel infestation than in recent years (30,000 dollars). As a result of this and other factors, early predictions of the ultimate costs of the zebra mussel invasion may have been excessive. PMID:17530329

Connelly, Nancy A; O'Neill, Charles R; Knuth, Barbara A; Brown, Tommy L

2007-07-01

54

The acoustic effect of vocal tract adjustments in zebra finches.  

Science.gov (United States)

Vocal production in songbirds requires the control of the respiratory system, the syrinx as sound source and the vocal tract as acoustic filter. Vocal tract movements consist of beak, tongue and hyoid movements, which change the volume of the oropharyngeal-esophageal cavity (OEC), glottal movements and tracheal length changes. The respective contributions of each movement to filter properties are not completely understood, but the effects of this filtering are thought to be very important for acoustic communication in birds. One of the most striking movements of the upper vocal tract during vocal behavior in songbirds involves the OEC. This study measured the acoustic effect of OEC adjustments in zebra finches by comparing resonance acoustics between an utterance with OEC expansion (calls) and a similar utterance without OEC expansion (respiratory sounds induced by a bilateral syringeal denervation). X-ray cineradiography confirmed the presence of an OEC motor pattern during song and call production, and a custom-built Hall-effect collar system confirmed that OEC expansion movements were not present during respiratory sounds. The spectral emphasis during zebra finch call production ranging between 2.5 and 5 kHz was not present during respiratory sounds, indicating strongly that it can be attributed to the OEC expansion. PMID:23085986

Riede, Tobias; Schilling, Nadja; Goller, Franz

2013-01-01

55

Co-existence of zebra mussels and freshwater unionids: Population dynamics of Leptodea fragilis in a coastal wetland infested with zebra mussels  

Science.gov (United States)

In 1996, thousands of live Leptodea fragilis were collected from a marsh located in the western basin of Lake Erie that was infested with zebra mussels (Dreissena polymorpha). Despite the presence of zebra mussels at this site for a number of years, this L. fragilis population showed no signs of competition-induced changes in population dynamics. Biofouling was limited: fewer than 1% of the L. fragilis showed evidence of recent or past zebra mussel colonization. Successful recruitment occurred yearly, with multiple year classes collected that ranged in age from 1 to 12 years. However, age and shell length were not well correlated. Seventy-one percent of the individuals collected were 51-80 mm long, but ranged in age from 2 to 4.5 years. Three different patterns of growth or shell deposition were found. Some individuals grew rapidly, reaching 105 mm in 3.5 years, while others grew only 4.5 mm over the same time period. A few grew poorly during some years but very rapidly in others. Individuals with a shell length of 41 mm or more were sexually mature and females were more common than males. The strong recruitment and steady growth of this population showed no change between the years before and after the zebra mussel invasion, indicating that this marsh is functioning as a natural refugium from potential problems caused by zebra mussels.

Nichols, S. Jerrine; Amberg, Jon

1999-01-01

56

Interactions among zebra mussel shells, invertebrate prey, and Eurasian ruffe or yellow perch  

Science.gov (United States)

The exotic zebra mussel, Dreissena polymorpha, is established in all of the Laurentian Great Lakes and may affect benthivorous fishes by increasing the complexity of benthic substrates and changing energy flow patterns within the food web. Native yellow perch, Perca flavescens, and the nonindigenous Eurasian ruffe, Gymnocephalus cernuus, are benthivores that may compete for limited food resources. As ruffe spread to areas with more dense zebra mussel populations, the zone of interaction among zebra mussels, yellow perch, and ruffe will increase and intensify. In the laboratory, the effect of zebra mussel shells on the ability of these fishes to forage on amphipods (Gammarus pseudolimnaeus) and chironomids (Chironomus plumosus) was examined in light and darkness. In 12 h, ruffe consumed more amphipods than did similar-sized yellow perch, particularly in darkness on bare cobble, and in light within zebra mussels. Amphipods decreased activity more in the presence of ruffe than yellow perch. More amphipods were found in zebra mussel shells than in bare cobble, whether or not fish were present. In darkness, when ruffe consumed more amphipods on bare cobble, amphipods became more associated with zebra mussel shells. Although ruffe consumed more amphipods than yellow perch, perch consumed more chironomids than ruffe on bare cobble. The presence of zebra mussel shells altered the relative consumption of invertebrates in some substrate-light combinations. Experiments such as these help to improve understanding of the direct and indirect effects of predation between and among native and nonindigenous species that may exert structuring forces on the nearshore communities of the Great Lakes currently or in the future.

Kolar, C. S.; Fullerton, A. H.; Martin, K. M.; Lamberti, G. A.

2002-01-01

57

Habitat engineering by the invasive zebra mussel Dreissena polymorpha (Pallas) in a boreal coastal lagoon: impact on biodiversity  

Science.gov (United States)

Habitat engineering role of the invasive zebra mussel Dreissena polymorpha (Pallas) was studied in the Curonian lagoon, a shallow water body in the SE Baltic. Impacts of live zebra mussel clumps and its shell deposits on benthic biodiversity were differentiated and referred to unmodified (bare) sediments. Zebra mussel bed was distinguished from other habitat types by higher benthic invertebrate biomass, abundance, and species richness. The impact of live mussels on biodiversity was more pronounced than the effect of shell deposits. The structure of macrofaunal community in the habitats with >103 g/m2 of shell deposits devoid of live mussels was similar to that found within the zebra mussel bed. There was a continuous shift in species composition and abundance along the gradient ‘bare sediments—shell deposits—zebra mussel bed’. The engineering impact of zebra mussel on the benthic community became apparent both in individual patches and landscape-level analyses.

Zaiko, Anastasija; Daunys, Darius; Olenin, Sergej

2009-03-01

58

Removal of algae by the zebra mussel (Dreissena polymorpha) population in western Lake Erie: a bioenergetics approach  

Science.gov (United States)

A bioenergetics model for growth of a zebra mussel (Dreissena polymorpha) individual was verified with observations on zebra mussel growth in western Lake Erie. The bioenergetics model was then applied to the zebra mussel population in the western basin of Lake Erie to estimate the removal of phytoplankton by mussels. According to the modeling results, the zebra mussel population consumed 5.0 million tonnes of phytoplankton, while 1.4 million tonnes of phytoplankton was deposited in pseudofeces from the mussels. Thus, a total of 6.4 A? 2.4 million tonnes of phytoplankton was removed from the water column by zebra mussel in western Lake Erie during 1990. Primary production was estimated to be 24.8 million tonnes; therefore, zebra mussel removed the equivalent of 26 A? 10% of the primary production for western Lake Erie.

Madenjian, Charles P.

1995-01-01

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Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus  

Science.gov (United States)

Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

Farsad, Nikrooz

60

Effect of Acute Stresses on Zebra Fish (Danio rerio) Metabolome Measured by NMR-Based Metabolomics.  

Science.gov (United States)

We applied an acute stress model to zebra fish in order to measure the changes in the metabolome due to biological stress. This was done by submitting the fish to fifteen minutes of acute confinement (netting) stress, and then five minutes for the open field and light/dark field tests. A polar extract of the zebra fish was then subjected to (1)H nuclear magnetic spectroscopy. Multivariate data analysis of the spectra showed a clear separation associated to a wide range of metabolites between zebra fish that were submitted to open field and light/dark field tests. Alanine, taurine, adenosine, creatine, lactate, and histidine were high in zebra fish to which the light/dark field test was applied, regardless of stress, while acetate and isoleucine/lipids appeared to be higher in zebra fish exposed to the open field test. These results show that any change in the environment, even for a small period of time, has a noticeable physiological impact. This research provides an insight of how different mechanisms are activated under different environments to maintain the homeostasis of the body. It should also contribute to establish zebra fish as a model for metabolomics studies. PMID:25098933

Mushtaq, Mian Yahya; Marçal, Rosilene Moretti; Champagne, Danielle L; van der Kooy, Frank; Verpoorte, Robert; Choi, Young Hae

2014-09-01

 
 
 
 
61

Interpretation of experiments made in ZEBRA CADENZA assemblies with CEA formulary  

International Nuclear Information System (INIS)

A benchmark exercise on fast critical heterogeneity method assessment has been proposed in the framework of NEACRP. It is based on the analysis of two integral experiments performed by UKAEA on the ZEBRA facility (the CADENZA assemblies): - a plate fuelled core (ZEBRA 22); - a 75% pin fuelled core (ZEBRA 23). The interpretation of these experiments has been done using the current standard CEA methods. We find a relevant (650 pcm) discrepancy between the ''k'' values of ZEBRA 22 and ZEBRA 23 pin assemblies. We try in this report to find out the origin of this discrepancy. The spatial k-value calculation results and corrections are affected by nomore than 150 pcm and are partially correlated. Moreover, this discrepancy does not seem to be explained in terms of homogenous infinite dilute cross section effects. It has been found that most of the discrepancy can be traced back to heterogeneity effects, and mainly to the heterogeneity effects of the metallic fuel plate in the metallic fuel plate in the ZEBRA 22 cell. Finally, the pin core gives, in the CEA analysis, a Keff E-C value well inside the known performance of the adjusted CARNAVAL IV formulaire (i.e. E-C =+ 300 + +500+-200 pcm) for plutonium fuelled cores

62

Unusual Zebra Patterns in the Decimeter Wave Band  

Science.gov (United States)

An analysis of new observations showing fine structures consisting of narrowband fiber bursts as substructures of large-scale zebra-pattern stripes is carried out. We study four events using spectral observations taken with a newly built spectrometer located at the Huairou station, China, in the frequency range of 1.1 - 2.0 GHz with extremely high frequency and time resolutions (5 MHz and 1.25 ms). All the radio events were analyzed by using the available satellite data (SOHO LASCO, EIT, and MDI, TRACE, and RHESSI). Small-scale fibers always drift to lower frequencies. They may belong to a family of ropelike fibers and can also be regarded as fine structures of type III bursts and broadband pulsations. The radio emission was moderately or strongly polarized in the ordinary wave mode. In three main events fiber structure appeared as a forerunner of the entire event. All four events were small decimeter bursts. We assume that for small-scale fiber bursts the usual mechanism of coalescence of whistler waves with plasma waves can be applied, and the large-scale zebra pattern can be explained in the conventional double plasma resonance (DPR) model. The appearance of an uncommon fine structure is connected with the following special features of the plasma wave excitation in the radio source: Both whistler and plasma wave instabilities are too weak at the very beginning of the events ( i.e., the continuum was absent), and the fine structure is almost invisible. Then, whistlers generated directly at DPR levels “highlight” the radio emission only from these levels owing to their interaction with plasma waves.

Chernov, G. P.; Yan, Yihua; Fu, Qijun; Tan, Chengming; Wang, Shujuan

2008-07-01

63

Putative identification of expressed genes associated with attachment of the zebra mussel (Dreissena polymorpha).  

Science.gov (United States)

Because of its aggressive growth and firm attachment to substrata, the zebra mussel (Dreissena polymorpha) has caused severe economic and ecological problems since its invasion into North America. The nature and details of attachment of this nuisance mollusc remains largely unexplored. Byssus, a special glandular apparatus located at the root of the foot of the mussel produces threads and plates through which firm attachment of the mollusc to underwater objects takes place. In an attempt to better understand the adhesion mechanism of the zebra mussel, the suppression subtractive hybridization (SSH) assay was employed to produce a cDNA library with genes unique to the foot of the mussel. Analysis of the SSH cDNA library revealed the presence of 750 new expressed sequence tags (ESTs) including 304 contigs and 446 singlets. Using BLAST search, 365 zebra mussel ESTs showed homology to other gene sequences with putative functions. The putative functions of the homologues included proteins involved in byssal thread formation in zebra and blue mussels, exocrine gland secretion, host defence, and house keeping. The generated data provide, for the first time, some useful insights into the foot structure of the zebra mussel and its underwater adhesion. PMID:18330781

Xu, Wei; Faisal, Mohamed

2008-01-01

64

Bioaccumulation of human waterborne protozoa by zebra mussel (Dreissena polymorpha): interest for water biomonitoring.  

Science.gov (United States)

Cryptosporidium parvum, Giardia duodenalis and Toxoplasma gondii are ubiquitous pathogens, which waterborne transmission has been largely demonstrated. Since they can be found in various watercourses, interactions with aquatic organisms are possible. Protozoan detection for watercourses biomonitoring is currently based on large water filtration. The zebra mussel, Dreissena polymorpha, is a choice biological model in ecotoxicological studies which are already in use to detect chemical contaminations in watercourses. In the present study, the zebra mussel was tested as a new tool for detecting water contamination by protozoa. In vivo exposures were conducted in laboratory experiments. Zebra mussel was exposed to various protozoan concentrations for one week. Detection of protozoa was realized by Taqman real time qPCR. Our experiments evidenced C. parvum, G. duodenalis and T. gondii oocyst bioaccumulation by mussels proportionally to ambient contamination, and significant T. gondii prevalence was observed in muscle tissue. To our knowledge, this is the first study that demonstrates T. gondii oocyst accumulation by zebra mussel. The results from this study highlight the capacity of zebra mussels to reveal ambient biological contamination, and thus to be used as a new effective tool in sanitary biomonitoring of water bodies. PMID:24112626

Palos Ladeiro, M; Aubert, D; Villena, I; Geffard, A; Bigot, A

2014-01-01

65

Some aspects of fast reactor operation studied in Zebra  

International Nuclear Information System (INIS)

Four aspects of the fast reactor operating cycle that have been experimentally investigated in Zebra are described. Sensitive radiochemical techniques for measuring the capture rates in 241Am and 243Am leading to 242Cm and 244Cm have been applied to samples irradiated in spectra characteristic of PFR and of a commercial-size reactor. The derived cross sections are compared with those predicted using recent evaluations. Gamma activities induced in a range of elements of potential significance to contamination of the primary circuit in core and axial-breeder locations have been determined by standardised liquid-source counting techniques. Samples of fuel-clad and subassembly-wrapper alloys have also been examined. Results are compared with predictions using currently-recommended cross-sections. The energy release by B-particles from fission products of 235U and 239Pu following a 105-second irradiation has been measured over a cooling period of 1 year using a catcher-foil technique and a plastic scintillation detector. Comparisons with summation-code predictions are presented. The formation of plutonium in a radial breeder has been simulated by replacing UO2 plates by PuO2/UO2 to give an average level of 2% Pu/U. The influence of this enrichment on the reaction rates of 235U, and 238U and 239Pu was measured by foil activation methods. Comparisons with diffusion and transport-theory calculations are made. (author)

66

Rotationally driven 'zebra stripes' in Earth's inner radiation belt.  

Science.gov (United States)

Structured features on top of nominally smooth distributions of radiation-belt particles at Earth have been previously associated with particle acceleration and transport mechanisms powered exclusively by enhanced solar-wind activity. Although planetary rotation is considered to be important for particle acceleration at Jupiter and Saturn, the electric field produced in the inner magnetosphere by Earth's rotation can change the velocity of trapped particles by only about 1-2 kilometres per second, so rotation has been thought inconsequential for radiation-belt electrons with velocities of about 100,000 kilometres per second. Here we report that the distributions of energetic electrons across the entire spatial extent of Earth's inner radiation belt are organized in regular, highly structured and unexpected 'zebra stripes', even when the solar-wind activity is low. Modelling reveals that the patterns are produced by Earth's rotation. Radiation-belt electrons are trapped in Earth's dipole-like magnetic field, where they undergo slow longitudinal drift motion around the planet because of the gradient and curvature of the magnetic field. Earth's rotation induces global diurnal variations of magnetic and electric fields that resonantly interact with electrons whose drift period is close to 24 hours, modifying electron fluxes over a broad energy range into regular patterns composed of multiple stripes extending over the entire span of the inner radiation belt. PMID:24646996

Ukhorskiy, A Y; Sitnov, M I; Mitchell, D G; Takahashi, K; Lanzerotti, L J; Mauk, B H

2014-03-20

67

Neural correlates of nesting behavior in zebra finches (Taeniopygia guttata).  

Science.gov (United States)

Nest building in birds involves a behavioral sequence (nest material collection and deposition in the nest) that offers a unique model for addressing how the brain sequences motor actions. In this study, we identified brain regions involved in nesting behavior in male and female zebra finches (Taeniopygia guttata). We used Fos immunohistochemistry to quantify production of the immediate early gene protein product Fos (a molecular indicator of neuronal activity) in the brain correlated this expression with the variation in nesting behavior. Using this technique, we found that neural circuitry involved in motor sequencing, social behavior, reward and motivation were active during nesting. Within pairs of nesting birds, the number of times a male picked up or deposited nesting material and the amount of time a female spent in the nest explained the variation in Fos expression in the anterior motor pathway, social behavior network, and reward neural circuits. Identification of the brain regions that are involved in nesting enables us to begin studying the roles of motor sequencing, context, and reward in construction behavior at the neural level. PMID:24508238

Hall, Zachary J; Bertin, Marion; Bailey, Ida E; Meddle, Simone L; Healy, Susan D

2014-05-01

68

Proteomic analyses of zebra finch optic tectum and comparative histochemistry.  

Science.gov (United States)

Proteomic analyses of zebra finch (Taeniopygia guttata) optic tectum resulted in identification of 176 proteins. In the Swissprot database, only 52 proteins were identified as bird homologs and only 71 proteins were identified in songbird transcriptome databases, reflecting a lack of completeness in the T. guttata genomic sequence. Analysis in Kyoto encyclopedia of genes and genome (KEGG) pathway database found that identified proteins most frequently belong to glucose, pyruvate, glyoxylate, dicarboxylate, alanine, and aspartate metabolism pathways. A number of identified proteins have been previously reported to exist in the avian optic tectum. The immunohistochemical localization of selected proteins showed their distribution in similar laminae of the owl (Tyto alba) and chicken (Gallus gallus) tectum. Immunohistochemical analysis of identified proteins can provide clues about cell types and circuit layout of the avian optic tectum in general. As the optic tectum of nonmammals is homologous to the superior colliculus of mammals, the analysis of the tectal and collicular proteome may provide clues about conserved cell and circuit layout, circuit function, and evolution. PMID:17497909

Sloley, Stephanie; Smith, Shannon; Gandhi, Sonia; Busby, Jennifer A Caldwell; London, Sarah; Luksch, Harald; Clayton, David F; Bhattacharya, Sanjoy K

2007-06-01

69

AFLP analysis and zebra disease resistance identification of 40 sisal genotypes in China.  

Science.gov (United States)

Sisal is the most important fiber crop in tropical and subtropical areas in China and the world. Zebra disease is a serious threat to the main cultivar Agave hybrid No.11648 (H.11648) worldwide. To select germplasm materials with zebra disease resistance for breeding, the fluorescent amplified fragment length polymorphism (AFLP) technique was used to make a cluster analysis of the genetic relationships of 40 sisal genotypes grown in China, and Phytophthora nicotianae was used to inoculate the 40 genotypes to identify their resistance to zebra disease. As a result, the similarity coefficient among 40 sisal genotypes was found to be 0.44-0.83 and the 40 genotypes show different levels of disease resistance. According to the AFLP analysis, the disease resistance and chromosomal ploidy, it can be reasoned that, A. attenuata var. marginata, Dong 109, Nan ya 1 and A. attenuata are suitable for hybridization with H.11648 to breed a new disease-resistant variety. PMID:22327644

Gao, Jianming; Luoping; Guo, Chaoming; Li, Jinzhi; Liu, Qiaolian; Chen, Helong; Zhang, Shiqing; Zheng, Jinlong; Jiang, Chenji; Dai, Zhenzhen; Yi, Kexian

2012-05-01

70

Scope of problem assessed at IVO. The zebra mussel`s campaign of world conquest  

Energy Technology Data Exchange (ETDEWEB)

The migrating shell - or `zebra mussel` as it is called on account of its black and white stripes - was originally a fresh-water mussel, but has since also adapted to brackish waters. As a result of human activity the species has spread quickly and widely from its native habitat. Operators of power plants and water treatment plants in particular have not been very happy about this. During its larval stage the zebra mussel can enter the cooling water systems; fasten itself to the pipes and - in the worst case - clog the system. The Environmental Protection Division of IVO has been assessing the spread of the zebra mussel and the resulting problems with the aid of reference literature and the assistance of Finnish researchers

Silvonen, J.; Oesch, P. [ed.

1998-07-01

71

Measurement and analysis of reaction rates in simulated PFR demountable subassembly heat-pins in ZEBRA  

International Nuclear Information System (INIS)

Measurements completed on the Zebra reactor to assess the reliability of current diffusion-theory predictions of the power generated in DMSA heater pins in PFR, are described. A range of heater pin configurations was simulated, and reaction rates of fission in Pu 239, U 238 and U 235 and capture in U 238 were measured. These were also calculated using standard Zebra methods. The calculated-to-experimental ratios were in the range 1.03 to 1.05, giving confidence in the methods of prediction used for PFR. (U.K.)

72

The ZEBRA electric vehicle battery: power and energy improvements  

Science.gov (United States)

Vehicle trials with the first sodium/nickel chloride ZEBRA batteries indicated that the pulse power capability of the battery needed to be improved towards the end of the discharge. A research programme led to several design changes to improve the cell which, in combination, have improved the power of the battery to greater than 150 W kg -1 at 80% depth of discharge. Bench and vehicle tests have established the stability of the high power battery over several years of cycling. The gravimetric energy density of the first generation of cells was less than 100 Wh kg -1. Optimisation of the design has led to a cell with a specific energy of 120 Wh kg -1 or 86 Wh kg -1 for a 30 kWh battery. Recently, the cell chemistry has been altered to improve the useful capacity. The cell is assembled in the over-discharged state and during the first charge the following reactions occur: at 1.6 V: Al+4NaCl=NaAlCl 4+3Na; at 2.35 V: Fe+2NaCl=FeCl 2+2Na; at 2.58 V: Ni+2NaCl=NiCl 2+2 Na. The first reaction serves to prime the negative sodium electrode but occurs at too low a voltage to be of use in providing useful capacity. By minimising the aluminium content more NaCl is released for the main reactions to improve the capacity of the cell. This, and further composition optimisation, have resulted in cells with specific energies in excess of 140 Wh kg -1, which equates to battery energies>100 Wh kg -1. The present production battery, as installed in a Mercedes Benz A class electric vehicle, gives a driving range of 205 km (128 miles) in city and hill climbing. The cells with improved capacity will extend the practical driving range to beyond 240 km (150 miles).

Galloway, Roy C.; Haslam, Steven

73

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development  

Science.gov (United States)

The zebra finch (Taeniopygiaguttata) has become an increasingly important model organism in many areas of research including toxicology1,2, behavior3, and memory and learning4,5,6. As the only songbird with a sequenced genome, the zebra finch has great potential for use in developmental studies; however, the early stages of zebra finch development have not been well studied. Lack of research in zebra finch development can be attributed to the difficulty of dissecting the small egg and embryo. The following dissection method minimizes embryonic tissue damage, which allows for investigation of morphology and gene expression at all stages of embryonic development. This permits both bright field and fluorescence quality imaging of embryos, use in molecular procedures such as in situ hybridization (ISH), cell proliferation assays, and RNA extraction for quantitative assays such as quantitative real-time PCR (qtRT-PCR). This technique allows investigators to study early stages of development that were previously difficult to access. PMID:24999108

Murray, Jessica R.; Stanciauskas, Monika E.; Aralere, Tejas S.; Saha, Margaret S.

2014-01-01

74

The Quantitative Ethology of the Zebra Finch: A Study in Comparative Psychometrics.  

Science.gov (United States)

A quantitative ethogram was developed for the zebra finch, using one-zero focal animal sampling on an ethologically comprehensive checklist of 52 behavioral items, and it was assessed for interobserver reliability and construct validity. Applying the quantitative methods of psychometrics allows verification of ethological theory and testing of…

Figueredo, Aurelio Jose; And Others

1992-01-01

75

A Generalizability Analysis of Subjective Personality Assessments in the Stumptail Macaque and the Zebra Finch.  

Science.gov (United States)

Two longitudinal studies involving 29 raters concerning the construct validity, temporal stability, and interrater reliability of the latent common factors underlying subjective assessments by human raters of personality traits in the stumptail macaque and the zebra finch illustrate the use of generalizability analysis to test prespecified…

Figueredo, Aurelio Jose; And Others

1995-01-01

76

Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults  

International Nuclear Information System (INIS)

Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

77

Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults  

Energy Technology Data Exchange (ETDEWEB)

Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

Navarro, Anna; Faria, Melissa; Barata, Carlos [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain); Pina, Benjamin, E-mail: bpcbmc@cid.csic.e [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain)

2011-01-15

78

Zebra: Searching for Rare Diseases : A Case of Task-Based Search in the Medical Domain  

DEFF Research Database (Denmark)

Task-based search addresses situations where standard off-the-shelf Information Retrieval (IR) technology may not suffice to satisfy users in their tasks. In these situations, IR systems should be tailored to the user’s task-specific needs and requirements. One such task is searching for rare disease diagnostic hypotheses in the domain of medical IR. In this work, we build upon an existing vertical medical search engine, Zebra, that is focused on rare disease diagnosis. In previous work, Zebra has been evaluated using real-life medical cases of rare and difficult diseases, and has been found to be a useful and competitive tool for clinicians. In this work, we extend Zebra’s functionalities to optimise the task of medical diagnosis through search as follows: we add the option of grouping retrieved documents into clusters based on disease name occurrence, and we offer a ‘disease-ranking’ option, in addition to the standard ‘document-ranking’ option. This paper presents and discusses these functionalities.

Dragusin, Radu; Petcu, Paula

2012-01-01

79

Characterization of metallothionein-like proteins from zebra mussels (Dreissena polymorpha)  

Energy Technology Data Exchange (ETDEWEB)

Zebra mussels (Dreissena polymorpha) are freshwater mollusks that have recently infested the Great Lakes ecosystem. Possessing a large capacity for filtration, these mussel populations act as bioconcentrators for contaminants, such as heavy metals, found in the Great Lakes ecosystem. Metallothionein is a low-molecular-weight, heavy metal-binding protein found in most living organisms. Characterization and partial purification of metallothionein-like Cd-binding proteins from zebra mussels were performed. Zebra mussels were exposed to 500 {micro}g/L Cd for 14 d. During the exposure period, two mussels were removed on alternate days for analysis of Cd-binding proteins. Gel-filtration high-performance liquid chromatography-microatomization-atomic absorption spectrophotometry results showed a single Cd-binding molecular weight protein fraction after 2 d of Cd exposure. After 10 d of Cd exposure, however, mussels exhibited an additional higher molecular weight, Cd-binding protein fraction. The lower molecular weight metallothionein-like Cd-binding protein was further isolated and purified by acetone fractionation, Sephadex G75, and diethylaminoethyl anion-exchange chromatography. The quantities of Zn, Cu, and Cd in the anion-exchange metallothionein-like protein isoforms were determined by inductively coupled plasma-mass spectrometry. The ability to bioconcentrate heavy metals in a metallothionein-like form coupled with their large population in the Great Lakes make zebra mussels suitable for use in a freshwater biomonitoring program for aquatic metal contamination.

High, K.A.; Barthet, V.J.; Blais, J.S. [McGill Univ., Sainte Anne de Bellevue, Quebec (Canada). Dept. of Food Science and Agricultural Chemistry; McLaren, J.W. [National Research Council of Canada, Ottawa, Ontario (Canada)

1997-06-01

80

Zebra Crossing: Walking in Two Continents Sharing and Celebrating Difference through Music  

Science.gov (United States)

I use the metaphor "zebra crossing" in my reflective narrative to describe my plight and struggle as a non-white person growing up and working in Johannesburg, South Africa, during the apartheid era. This article considers and compares the notions of culture, diversity and identity as I now work in a tertiary institution in Melbourne, Australia. I…

Joseph, Dawn

2011-01-01

 
 
 
 
81

Cultivation of zebra mussels (Dreissena polymorpha) within their invaded range to improve water quality in reservoirs.  

Science.gov (United States)

Algal and cyanobacterial blooms in reservoirs are driven by nutrient enrichment and may present economic and conservation challenges for water managers. Current approaches such as suppression of algal growth with barley straw, ferric dosing or manipulation of fish stocks have not yielded long term successes. A possibility that has sparked growing interest is the encouragement and cultivation of natural filter feeders, such as mussels, which remove suspended matter from the water and reduce nutrient levels through biodeposition and assimilation. This review focusses on the zebra mussel (Dreissena polymorpha) as a tool for enhancement of water quality in reservoirs. Native to the Ponto-Caspian region, this species has invaded many lakes and reservoirs across North America and Western Europe, where it occurs in very high densities. While purposeful introduction of a non-native species into new sites is socially unacceptable, we investigate the possible benefits of encouraging increased abundance of zebra mussels in sites where the species is already established. We estimate that the annual nitrogen and phosphorus input into a large UK reservoir (Grafham Water) could be assimilated into zebra mussel biomass by encouraging settlement onto 3075 m and 1400 m of commercial mussel ropes, respectively. While zebra mussel cultivation has an incredible capacity to push eutrophic systems towards a clear water state, there are many risks associated with encouraging an invasive species, even within sites where it has already established. The zebra mussel is a prominent biofouler of native unionid mussels and raw water pipes, it changes the physical characteristics of the places it inhabits, in sites low in phosphorus it can be responsible for toxic cyanobacterial blooms, it alters nutrient cycling and community structure and it can have negative impacts on amenity value. Increased propagule pressure from elevated numbers of veliger larvae in the water column may increase the risk of spread to other locations. This may render some reservoir systems, such as dammed rivers which have outflows to downstream watercourses, unsuitable for cultivation. Such reservoirs are especially common in North America. We consider the practicalities of putting a zebra mussel cultivation system into place and identify gaps in knowledge. We conclude that zebra mussel cultivation offers an attractive tool for managing nutrient-enriched reservoirs, but that the benefits and costs must be balanced on a site-by-site basis. PMID:23764587

McLaughlan, C; Aldridge, D C

2013-09-01

82

Comparative genomic analysis of the zebra finch degradome provides new insights into evolution of proteases in birds and mammals  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The degradome -the complete repertoire of proteases in an organism- is involved in multiple key biological and pathological processes. Previous studies in several organisms have yielded sets of curated protease sequences which may be used to characterize the degradome in a novel genome by similarity. Differences between degradomes can then be related to physiological traits of the species under study. Therefore, the sequencing of the zebra finch genome allows the comparison between the degradomes of mammals and birds and may help to understand the biological peculiarities of the zebra finch. Results A set of curated protease sequences from humans and chicken was used to predict the sequences of 460 protease and protease-like genes in the zebra finch genome. This analysis revealed important differences in the evolution of mammalian and bird degradomes, including genomic expansions and deletions of caspases, cytotoxic proteases, kallikreins, matrix metalloproteases, and trypsin-like proteases. Furthermore, we found several zebra finch-specific features, such as duplications in CASP3 and BACE, and a large genomic expansion of acrosin. Conclusions We have compared the degradomes of zebra finch, chicken and several mammalian species, with the finding of multiple differences which illustrate the evolution of the protease complement of these organisms. Detailed analysis of these changes in zebra finch proteases has shown that they are mainly related to immunological, developmental, reproductive and neural functions.

López-Otín Carlos

2010-04-01

83

Effect of the zebra mussel (Dreissena polymorpha) on food-chain transfer of PCBs in Saginaw Bay  

Energy Technology Data Exchange (ETDEWEB)

The recent invasion of the zebra mussel (Dreissena polymorpha) has significantly impacted the water quality of the Great Lakes. Relatively little is known about the influence of zebra mussels on contaminant cycling, and transfer to higher trophic organisms. Due to its high filtering rate and ability to rapidly establish large populations, Dreissena could potentially alter the flow of energy through the food web. In addition, this species has demonstrated a large capacity for accumulating lipophilic organic contaminants such as polychlorinated biphenyls (PCBs). Thus, zebra mussels could contribute to enhanced contaminant biomagnification by serving as an additional food-chain link either through direct transfer (ingestion by fish or ducks), and/or indirectly by funneling contaminants out of the pelagic zone down to benthic invertebrates. In order to determine if zebra mussels are enhancing biomagnification of PCBs in a Saginaw Bay food web, two years of field collections of various components (water, sediment, algae, zooplankton, zebra mussel, zebra mussel feces, gammarid amphipods, fish) were analyzed for their PCB congener content. Trophic levels will be characterized using stable isotope ratios of {sup 15}N/{sup 14}N, whereas carbon sources will be identified using {sup 13}C/{sup 13}C ratios.

Hoof, P.L. Van; Hsieh, J.L.; Eadie, B.J.; Lansing, M.B. [NOAA, Ann Arbor, MI (United States). Great Lakes Environmental Research Lab.

1995-12-31

84

Social learning of food types in zebra finches (Taenopygia guttata) is directed by demonstrator sex and feeding activity.  

Science.gov (United States)

In this study we examined how social learning of feeding preferences by zebra finches was affected by the identity of different demonstrators. We presented adult zebra finches with two demonstrators, one male and one female, that exhibited different food choices, and we recorded their subsequent preference when given a choice between the two food types. Previously it was found that young zebra finches' patterns of social learning are affected by the sex of the individual demonstrating a feeding behaviour. This result could be explained by the lack of exposure these animals had to the opposite sex, or by their mating status. Therefore, we investigated the social learning preferences of adult mated zebra finches. We found the same pattern of directed social learning of a different type of feeding behaviour (food colour): female zebra finches preferred the colour of food eaten by male demonstrators, whereas male zebra finches showed little evidence of any preference for the colour of food eaten by female demonstrators. Furthermore, we found that female observers' preferences were biased by demonstrators' relative feeding activity: the female demonstrator was only ever preferred if it ate less than its male counterpart. PMID:12658531

Katz, M; Lachlan, R F

2003-03-01

85

Genomic and neural analysis of the estradiol-synthetic pathway in the zebra finch  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Steroids are small molecule hormones derived from cholesterol. Steroids affect many tissues, including the brain. In the zebra finch, estrogenic steroids are particularly interesting because they masculinize the neural circuit that controls singing and their synthesis in the brain is modulated by experience. Here, we analyzed the zebra finch genome assembly to assess the content, conservation, and organization of genes that code for components of the estrogen-synthetic pathway and steroid nuclear receptors. Based on these analyses, we also investigated neural expression of a cholesterol transport protein gene in the context of song neurobiology. Results We present sequence-based analysis of twenty steroid-related genes using the genome assembly and other resources. Generally, zebra finch genes showed high homology to genes in other species. The diversity of steroidogenic enzymes and receptors may be lower in songbirds than in mammals; we were unable to identify all known mammalian isoforms of the 3?-hydroxysteroid dehydrogenase and 17?-hydroxysteroid dehydrogenase families in the zebra finch genome assembly, and not all splice sites described in mammals were identified in the corresponding zebra finch genes. We did identify two factors, Nobox and NR1H2-RXR, that may be important for coordinated transcription of multiple steroid-related genes. We found very little qualitative overlap in predicted transcription factor binding sites in the genes for two cholesterol transport proteins, the 18 kDa cholesterol transport protein (TSPO and steroidogenic acute regulatory protein (StAR. We therefore performed in situ hybridization for TSPO and found that its mRNA was not always detected in brain regions where StAR and steroidogenic enzymes were previously shown to be expressed. Also, transcription of TSPO, but not StAR, may be regulated by the experience of hearing song. Conclusions The genes required for estradiol synthesis and action are represented in the zebra finch genome assembly, though the complement of steroidogenic genes may be smaller in birds than in mammals. Coordinated transcription of multiple steroidogenic genes is possible, but results were inconsistent with the hypothesis that StAR and TSPO mRNAs are co-regulated. Integration of genomic and neuroanatomical analyses will continue to provide insights into the evolution and function of steroidogenesis in the songbird brain.

London Sarah E

2010-04-01

86

Gene expression profiling during the byssogenesis of zebra mussel (Dreissena polymorpha).  

Science.gov (United States)

Since its invasion to the North American waters 20 years ago, the zebra mussel (Dreissena polymorpha) has negatively impacted the ecosystems through its firm underwater adhesion. The molecular mechanisms governing the functions of the zebra mussel byssus, the main structure responsible for maintaining the underwater adhesion, have received little attention. Our previously developed zebra mussel foot byssus cDNA microarray was applied in this study to identify the genes involved in different stages of the byssal threads generation. Byssal threads of zebra mussels were manually severed under laboratory conditions and the formation of new byssal threads was followed over a 3 week course. By comparing the gene expression profiles in different stages of byssal threads generation (byssogenesis) to their baseline values, we found that the number of unique byssus genes differentially expressed at 12-h, 1, 2, 3, 4, 7, and 21 days post-treatment was 13, 13, 20, 17, 16, 20, and 29, respectively. Comparisons were also made between two subsequent samples (e.g., 12 h vs. 1, 1 vs. 2 days, 2 vs. 3 days, and so on). Seven differentially expressed genes were selected for validation by using quantitative reverse transcription PCR (qRT-PCR) and the results were consistent with those from the microarray analysis. By using fluorescent in situ hybridization, we found that two microarray identified genes, BG15_F03-DPFP and BG16_H05-EGP, were expressed in two major byssus glands located in the zebra mussel foot: the stem-forming gland and plaque-forming gland, respectively. Moreover, the qRT-PCR of seven microarray identified genes with different zebra mussel samples suggested that they were also expressed in other mussel tissues beside the foot, albeit at much lower levels. This suggested that the microarray identified genes were produced primarily by the foot, and were likely associated with byssogenesis. The differentially expressed genes identified in this study indicated that multiple molecules are involved in byssogenesis, most likely performing multiple functions during the generation of byssal threads. These results obtained herein represent the first logical step toward understanding underwater attachment mechanisms employed by this invasive species. PMID:20148265

Xu, Wei; Faisal, Mohamed

2010-04-01

87

Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia adhesion  

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Full Text Available Abstract Background The zebra mussel (Dreissena polymorpha has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. Results In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A, current velocity (Factor B, dissolved oxygen (Factor C, and byssogenesis status (Factor D. Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR. The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. Conclusions The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment.

Faisal Mohamed

2010-05-01

88

Chemical defense in the zebra swallowtail butterfly, Eurytides marcellus, involving annonaceous acetogenins.  

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Few herbivores feed on the foliage of the North American paw paw tree, Asimina triloba; notable exceptions are the larvae of the zebra swallowtail butterfly, Eurytides marcellus. Toxic annonaceous acetogenins, produced by A. triloba, are responsible for the relative unpalatability of the leaves. Acetogenins found in A. triloba extracts are potent pesticidal and antineoplastic agents and have emetic activity in vertebrates. In this study, partitioned aqueous MeOH fractions of the bioactive CH2Cl2 extracts, of freeze-dried and pulverized larvae, and of mature butterflies revealed acetogenin content through the use of HPLC coupled to tandem MS (LC-MS/MS). This sensitive technique provides an uncomplicated method for the detection of trace compounds and, in this instance, has confirmed tissue presence of acetogenins that serve a probable role as chemical defense agents against bird predation in zebra swallowtail larvae and adults. PMID:9917274

Martin, J M; Madigosky, S R; Gu, Z M; Zhou, D; Wu, J; McLaughlin, J L

1999-01-01

89

Sobre la validez taxonómica de Epithemia Zebra var. Elongata (Epithemiaceae, Bacillariophyceae  

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Full Text Available Gorritti, G., Sala, S. E. & Guerrero, J. M. 2000. Sobre la validez taxonómica de Epithemiazebra var. elongata (Epithemiaceae, Bacillariophyceae. Darwiniana 38(3-4: 285-289.Se revisaron materiales de Epithemia zebra var. elongata Grunow ex Frenguelli para establecer lavalidez de este taxón. Se estudiaron con microscopio óptico y electrónico de barrido, ejemplares de lacolección Frenguelli y otros recientemente coleccionados en Tierra del Fuego . El análisis de la variaciónpoblacional de los caracteres morfológicos y morfométricos, y la comparación con los taxones afines:Epithemia adnata (Kützing Brébisson y E. adnata var. minor (Peragallo & Héribaud Patrick, demostróque no existen diferencias entre ellos por lo que E. zebra var. elongata debe ser considerada sinónimo deE. adnata

Gabriela Gorritti

2000-01-01

90

A model of so-called "Zebra" emissions in solar flare radio burst continua  

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Full Text Available A simple mechanism for the generation of electromagnetic "Zebra" pattern emissions is proposed. "Zebra" bursts are regularly spaced narrow-band radio emissions on the otherwise broadband radio continuum emitted by the active solar corona. The mechanism is based on the generation of an ion-ring distribution in a magnetic mirror geometry in the presence of a properly directed field-aligned electric potential field. Such ion-rings or ion-conics are well known from magnetospheric observations. Under coronal conditions they may become weakly relativistic. In this case the ion-cyclotron maser generates a number of electromagnetic ion-cyclotron harmonics which modulate the electron maser emission. The mechanism is capable of switching the emission on and off or amplifying it quasi-periodically which is a main feature of the observations.

R. A. Treumann

2011-09-01

91

Functional organisation of the field-L-complex of adult male zebra finches.  

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Functional maps of auditory response areas were established from multiunit recordings in the caudal telencephalon of male zebra finches. The response criterion was a difference of activity from the spontaneous discharge level. Pure tones and conspecific song were used as stimuli. The auditory part of the caudal telencephalon in zebra finches can be subdivided into six functionally separated centres. The definition of separate areas is based on the existence of tonotopic gradients in each single area and on differences in neural response behaviour between areas. The anatomical area L2a is functionally subdivided into two tonotopic centres. Other areas can be identified by anatomy and function. The borders vary slightly depending on the description method. PMID:10203338

Gehr, D D; Capsius, B; Gräbner, P; Gahr, M; Leppelsack, H J

1999-02-01

92

Diet, maternal condition, and offspring sex ratio in the zebra finch, Poephila guttata  

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Where maternal condition affects condition and reproductive potential of offspring differentially with respect to sex, mothers in relatively good condition should produce more of the sex whose fitness is more dependent on condition. We experimentally manipulated body-condition in unmated zebra finches by feeding them for three months on high- or low-quality diets. Birds were then allowed to breed, while keeping the same diets. Females on the lower quality diet were in better condition and hat...

Bradbury, R. B.; Blakey, J. K.

1998-01-01

93

Colour bands, dominance, and body mass regulation in male zebra finches (Taeniopygia guttata)  

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The arbitrary assignment of different coloured leg bands to zebra finches (Taeniopygia guttata) has profound effects on mate preference, reproductive success, mortality rates, parental investment and sex ratio. Choice chamber experiments indicate that the effect is mediated by altered attractiveness to members of the opposite sex. Effects on intrasexual dominance are more equivocal. We present two experiments which demonstrate significant effects of band colour on behavioural dominance (red b...

Cuthill, I. C.; Hunt, S.; Cleary, C.; Clark, C.

1997-01-01

94

Same-sex partner preference in zebra finches: pairing flexibility and choice.  

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This study examined flexibility and choice in same-sex pair-bonding behavior in adult zebra finches (Taeniopygia guttata). Zebra finches form life-long monogamous relationships and extra pair behavior is very low, making them an ideal species in which to study same-sex pairing. We examined same-sex behaviors using both semi-naturalistic choice paradigms and skewed sex ratios. In the first experiment, we allowed zebra finches to pair in aviaries with equal sex ratios as part of multiple experiments. On average, 6.4 % (N = 78) of unmanipulated pairs were same-sex: all but one was female-female. In a second experiment, we identified pairs from same-sex cages and selected 20 total same-sex pairs (10 of each sex). We then gave pairs a chance to court and pair with members of the opposite sex and observed their behavior for three days. Females did not retain their partner, but most paired with males. In contrast, some males did retain their partner. Similarly, females were more likely to engage in pairing behaviors with males than with their partners or other females whereas males were equally likely to engage in same-sex and opposite-sex pairing behaviors. These findings suggest that same-sex partnerships in zebra finches can be facultative, based on the sex ratio of the group in which they live, but can also be a choice, when opportunities to pair with opposite-sex individuals are possible. Furthermore, it is possible that females are more flexible in this choice of same-sex partnerships than are males. PMID:25190500

Tomaszycki, Michelle L; Zatirka, Brendon P

2014-11-01

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Canal construction destroys the barrier between major European invasion lineages of the zebra mussel.  

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Since the mid-1980s the zebra mussel, Dreissena polymorpha, Pallas 1771, has become the protagonist of a spectacular freshwater invasion in North America due to its large economic and biological impact. Several genetic studies on American populations have failed to detect any large-scale geographical patterns. In western Europe, where D. polymorpha has been a classical invader from the Pontocaspian since the early 19th century, the situation is strikingly different. Here, we show with genetic...

Mu?ller, Jakob C.; Hidde, Dennis; Seitz, Alfred

2002-01-01

96

Microencapsulated BioBullets for the control of biofouling zebra mussels.  

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The widespread invasion of freshwaters by the zebra mussel, Dreissena polymorpha, during the last 2 decades has made it one of the world's most economically and ecologically important pests. Since arriving in the North American Great Lakes in the 1980s, zebra mussels have become a major biofouler, blocking the raw water cooling systems of power stations and water treatment works and costing U.S. dollars 1-5 billion per year. Despite the development of numerous control methods, chlorination remains the only widespread and licensed technique. Zebra mussels are able to sense chlorine and othertoxins in their surrounding environment and respond by closing their valves, thus enabling them to avoid toxic effects for up to 3 weeks. Furthermore, prolonged dosing of chlorine in raw water produces ecotoxic trihalomethanes (THMs) by reaction with organic material in the water. We have developed a novel, environmentally safe, and effective method for controlling the zebra mussel: the BioBullet. Our method uses the encapsulation of an active ingredient (KCI) in microscopic particles of edible material. The mussels' natural filtering ability then removes and concentrates the particles from the water, without stimulating the valve-closing response. By using the mussels' filtering behavior to concentrate BioBullets the absolute quantity of active ingredient added to the water can be reduced substantially. Our approach allows us to engineer the particles to break up and dissolve completely within a few hours, thus eliminating the risk of polluting the wider ecosystem. We demonstrate that the effectiveness of a toxin in the control of biofouling filter-feeders can be enhanced greatly by using our technique. This paves the way for a new approach to the control of some of the world's most important economic pests. PMID:16509345

Aldridge, David C; Elliott, Paul; Moggridge, Geoff D

2006-02-01

97

The Invasion of the Zebra Mussel - Effects on Phytoplankton Community Structure and Ecosystem Function  

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Biological invasion has become a major threat to economy, ecology, global biodiversity and ecosystem function of aquatic ecosystems. The main aim of the thesis was to study the effects of the zebra mussel (Dreissena polymorpha), a versatile invasive species, on phytoplankton dynamics and ecosystem function of lakes. In a first attempt, I compared the density of Dreissena and the physicochemical data of ecosystems that it invaded among North American and European lakes to identify important f...

Naddafi, Rahmat

2007-01-01

98

Bioaccumulation and effects of perfluorinated compounds (PFCs) in zebra mussels (Dreissena polymorpha).  

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Perfluorinated chemicals (PFCs) have been used for many years in numerous industrial products and are known to accumulate in organisms. A recent survey showed that tissue levels of PFCs in aquatic organisms varied among compounds and species being undetected in freshwater zebra mussels Dreissena polymorpha. Here we studied the bioaccumulation kinetics and effects of two major PFCs, perfluorooctane sulfonic acid compound (PFOS) and perfluorooctanoic acid (PFOA), in multixenobiotic transporter activity (MXR) and filtration and oxygen consumption rates in zebra mussel exposed to a range of concentrations of a PCF mixture (1-1,000 ?g/L) during 10 days. Results indicate a low potential of the studied PFCs to bioaccumulate in zebra mussel tissues. PFCs altered mussel MXR transporter activity being inhibited at day 1 but not at day 10. Bioaccumulation kinetics of PFCs were inversely related with MXR transporter activity above 9 ng/g wet weight and unrelated at tissue concentration lower than 2 ng/g wet weight suggesting that at high tissue concentrations, these type of compounds may be effluxed out by MXR transporters and as a result have a low potential to be bioaccumulated in zebra mussels. Oxygen consumption rates but not filtering rates were increased in all exposure levels and periods indicating that at environmental relevant concentrations of 1 ?g/L, the studied PFCs enhanced oxidative metabolism of mussels. Overall, the results obtained in this study confirm previous findings in the field indicating that an important fraction of PFC accumulated in mussel tissues is eliminated actively by MXR transporters or other processes that are metabolically costly. PMID:22990576

Fernández-Sanjuan, María; Faria, Melissa; Lacorte, Silvia; Barata, Carlos

2013-04-01

99

Oscillating magnetic field disrupts magnetic orientation in Zebra finches, Taeniopygia guttata  

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Abstract Background Zebra finches can be trained to use the geomagnetic field as a directional cue for short distance orientation. The physical mechanisms underlying the primary processes of magnetoreception are, however, largely unknown. Two hypotheses of how birds perceive magnetic information are mainly discussed, one dealing with modulation of radical pair processes in retinal structures, the other assuming that iron deposits in the upper beak of the birds are involved. O...

Wiltschko Wolfgang; Wiltschko Roswitha; Thalau Peter; Voss Joe; Ruploh Tim; Keary Nina; Bischof Hans-Joachim

2009-01-01

100

Oscillating magnetic field disrupts magnetic orientation in Zebra finches, Taeniopygia guttata  

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Background Zebra finches can be trained to use the geomagnetic field as a directional cue for short distance orientation. The physical mechanisms underlying the primary processes of magnetoreception are, however, largely unknown. Two hypotheses of how birds perceive magnetic information are mainly discussed, one dealing with modulation of radical pair processes in retinal structures, the other assuming that iron deposits in the upper beak of the birds are involved. Oscillating magnetic fields...

Keary, Nina; Ruploh, Tim; Voss, Joe; Thalau, Peter; Wiltschko, Roswitha; Wiltschko, Wolfgang; Bischof, Hans-joachim

2009-01-01

 
 
 
 
101

Zebra Finch Mates Use Their Forebrain Song System in Unlearned Call Communication  

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Unlearned calls are produced by all birds whereas learned songs are only found in three avian taxa, most notably in songbirds. The neural basis for song learning and production is formed by interconnected song nuclei: the song control system. In addition to song, zebra finches produce large numbers of soft, unlearned calls, among which “stack” calls are uttered frequently. To determine unequivocally the calls produced by each member of a group, we mounted miniature wireless microphones on each zebra finch. We find that group living paired males and females communicate using bilateral stack calling. To investigate the role of the song control system in call-based male female communication, we recorded the electrical activity in a premotor nucleus of the song control system in freely behaving male birds. The unique combination of acoustic monitoring together with wireless brain recording of individual zebra finches in groups shows that the neuronal activity of the song system correlates with the production of unlearned stack calls. The results suggest that the song system evolved from a brain circuit controlling simple unlearned calls to a system capable of producing acoustically rich, learned vocalizations. PMID:25313846

Ter Maat, Andries; Trost, Lisa; Sagunsky, Hannes; Seltmann, Susanne; Gahr, Manfred

2014-01-01

102

Diversity and temporal stability of bacterial communities in a model passerine bird, the zebra finch.  

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The composition and dynamics of the gastrointestinal bacterial communities in birds is determined by both host-specific and environmental exposure factors yet these are poorly understood. We selected the zebra finch, Taeniopygia guttata, as the host species to examine the diversity and temporal stability of the faecal microflora in a bird, owing to its importance as a model organism in avian ecology, neuroscience and evolution studies. The stability of the gut bacterial community of individual male and female zebra finches was assessed through repeat faecal sampling via culture and temperature gradient gel electrophoresis and partial sequencing of PCR-amplified eubacterial 16S rRNA gene products. Nineteen bacterial genera were detected across all samples (n = 99), with each bird carrying on average six operational taxonomic units. Using a novel statistical approach, we showed that bacterial assemblages and community richness varied between individual birds but remained stable over time within individuals. Neither the composition nor richness of bacterial communities differed significantly between the sexes. Our results show that zebra finches housed together under controlled conditions show consistent variation between individuals in their gut microflora that is not attributable to differences in host exposure to environmental microbial sources. Future studies could usefully explore the origin of this individual-specific variation and its consequences for host fitness and sexual selection. PMID:21054607

Benskin, Clare McW H; Rhodes, Glenn; Pickup, Roger W; Wilson, Kenneth; Hartley, Ian R

2010-12-01

103

Castration modulates singing patterns and electrophysiological properties of RA projection neurons in adult male zebra finches.  

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Castration can change levels of plasma testosterone. Androgens such as testosterone play an important role in stabilizing birdsong. The robust nucleus of the arcopallium (RA) is an important premotor nucleus critical for singing. In this study, we investigated the effect of castration on singing patterns and electrophysiological properties of projection neurons (PNs) in the RA of adult male zebra finches. Adult male zebra finches were castrated and the changes in bird song assessed. We also recorded the electrophysiological changes from RA PNs using patch clamp recording. We found that the plasma levels of testosterone were significantly decreased, song syllable's entropy was increased and the similarity of motif was decreased after castration. Spontaneous and evoked firing rates, membrane time constants, and membrane capacitance of RA PNs in the castration group were lower than those of the control and the sham groups. Afterhyperpolarization AHP time to peak of spontaneous action potential (AP) was prolonged after castration.These findings suggest that castration decreases song stereotypy and excitability of RA PNs in male zebra finches. PMID:24765586

Wang, Songhua; Liao, Congshu; Li, Fengling; Liu, Shaoyi; Meng, Wei; Li, Dongfeng

2014-01-01

104

Investigation of Acute Toxicity Diazinon, Deltamethrin, Butachlor and pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus  

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Full Text Available Background: The presence of pesticide due to the huge demand for agricultural purposes is very prevalent in surface waters of Iran. These pesticides could finally accumulate in aquatic ecosystems and have been proved to have toxic effects on aquatic animals. The aim of this study was to assess the acute toxicity of Diazinon, Deltamethrin, Butachlor and Pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus. Methods: Fish samples were exposed to different concentrations of Diazinon (60% (0, 2, 4, 8, 16 and 32 ppm, Deltamethrin (2.5% (0, 0.02, 0.04, 0.10, 0.20 and 0.40 ppm, butachlor (60% (0, 2, 4, 8, 16 and 32 ppm and pretilachlor (50% (0, 5, 10, 20, 30 and 40 ppm for 96 h within the 100 L glass aquaria and cumulative mortality of Zebra Cichlid fish was calculated in 24-h interval. Results: The very low LC50 obtained for diazinon (5.06±0.37 ppm, deltamethrin (0.15±0.39 ppm, butachlor (8.93±0.26 ppm and pretilachlor (20.72±0.58 ppm indicated that these are highly toxic chemicals. Conclusion: Our results demonstrate that deltamethrin and pretilachlor had the lowest and highest rate of mortality on the Zebra Cichlid respectively.

Ali Sadeghi

2014-06-01

105

Drivers and Controls of the Zebra Mussel Invasion of the Mississippi-Missouri River System  

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The zebra mussel Dreissena polymorpha has been haunting North American inland waters for the past twenty years. Due to the huge population densities reached by local colonies and the species' unparalleled dispersal ability, the zebra mussel represents a major threat from both an ecological and an economic perspective. We propose a novel ecohydrological model for the invasion of inland waters by this alien species and test it against field data gathered within the Mississippi-Missouri river system in North America. To incorporate both hydrologic controls and anthropogenic drivers of the invasion, the proposed multi-layer network model accounts explicitly for zebra mussel demographic dynamics, hydrologic transport and dispersal due to human activities. We show that hydrologic transport alone is not sufficient to explain the spread of the species at the basin scale. We also quantify the role played by commercial navigation in promoting the initial, selective colonization of the river system and show how recreational boating may have determined the capillary penetration of the species into the water system. The role of post-establishment dispersal mechanisms and the effectiveness of possible prevention measures are also discussed in the context of model sensitivity and robustness to reparameterization.

Casagrandi, R.; Mari, L.; Bertuzzo, E.; Gatto, M.; Levin, S. A.; Rodriguez-Iturbe, I.; Rinaldo, A.

2010-12-01

106

The assimilation of contaminants from suspended sediment and algae by the zebra mussel, Dreissena polymorpha.  

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Since their invasion into the Great Lakes, zebra mussels, Dreissena polymorpha, have increased the water clarity in Lake St. Clair and Lake Erie due to their extensive particle filtration. Because these particles contain sorbed contaminants, the potential for contaminant accumulation from both suspended sediment and algae were examined. Sediment or algae were dosed with selected radiolabeled polycyclic aromatic hydrocarbon congeners and/or hexachlorobiphenyl (HCBP). Assimilation efficiencies were measured and depended on food quality. Zebra mussels, 17 +/- 2 mm long, assimilated 58.3 +/- 13.5% of the pyrene and 44.7 +/- 5.8% of the benzo(a)pyrene (BaP) from sediment particles with a particle clearance rate of 493-897 ml/g tissue/h. However, assimilation efficiencies were 91.7 +/- 3.7% for pyrene, 91.9 +/- 1.4% for BaP, 96.6 +/- 1.4% for chrysene, and 97.7 +/- 0.5% for HCBP from suspended algae. Algal particle clearance rates for the mussels ranged from 47-143 ml/g tissue/h. Thus, zebra mussels efficiently accumulated non-polar contaminants sorbed to algae, while a smaller fraction of the sediment-associated contaminant was bioavailable. Furthermore, the contaminants sorbed onto suspended sediment particles were quickly removed from the water and deposited as pseudofeces. The pseudofeces production was positively correlated with filtration rate and suspended particle concentrations. PMID:9747518

Gossiaux, D C; Landrum, P F; Fisher, S W

1998-06-01

107

Bill redness is positively associated with reproduction and survival in male and female zebra finches.  

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Sexual traits can serve as honest indicators of phenotypic quality when they are costly. Brightly coloured yellow to red traits, which are pigmented by carotenoids, are relatively common in birds, and feature in sexual selection. Carotenoids have been linked to immune and antioxidant function, and the trade-off between ornamentation and these physiological functions provides a potential mechanism rendering carotenoid based signals costly. Mutual ornamentation is also common in birds and can be maintained by mutual mate choice for this ornament or by a correlated response in one sex to selection on the other sex. When selection pressures differ between the sexes this can cause intralocus sexual conflict. Sexually antagonistic selection pressures have been demonstrated for few sexual traits, and for carotenoid-dependent traits there is a single example: bill redness was found to be positively associated with survival and reproductive output in male zebra finches, but negatively so in females. We retested these associations in our captive zebra finch population without two possible limitations of this earlier study. Contrary to the earlier findings, we found no evidence for sexually antagonistic selection. In both sexes, individuals with redder bills showed higher survival. This association disappeared among the females with the reddest bills. Furthermore, females with redder bills achieved higher reproductive output. We conclude that bill redness of male and female zebra finches honestly signals phenotypic quality, and discuss the possible causes of the differences between our results and earlier findings. PMID:22808243

Simons, Mirre J P; Briga, Michael; Koetsier, Egbert; Folkertsma, Remco; Wubs, Matthias D; Dijkstra, Cor; Verhulst, Simon

2012-01-01

108

Zebra mussels (Dreissena polymorpha) as indicators of freshwater contamination with lindane  

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Zebra mussels are common freshwater mollusks in many European lakes and rivers. Their abundance, wide distribution, and filtering activity make them good candidates to evaluate the contamination of fresh waters with environmental contaminants. The purpose of this work was to determine the kinetics of lindane in zebra mussels and compare laboratory results with in situ measurements. Exposure was conducted in small tanks, under controlled experimental conditions. Our results indicated that mussels accumulated lindane with a bioconcentration factor around 10. They generally reached equilibrium within 4 days. Elimination was rapid but biphasic and the terminal elimination half-life was long (>168 h). Age of the mussels and temperature also affected the kinetics of lindane in mussels. In the Lake of eneva, zebra mussels were sampled and showed that mussels accumulated it to significant values (up to 900 ng/g fresh weight) depending on the site and period of sampling. The in situ results, together with the laboratory exposures, showed that freshwater mussels could be used to monitor point sources of pollutants such as lindane over short periods of time (<1 week)

109

Gene duplication and fragmentation in the zebra finch major histocompatibility complex  

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Full Text Available Abstract Background Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. Results The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. Conclusion The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene duplication and translocation in the history of the MHC in birds, and highlight striking differences in MHC structure and organization among avian lineages.

Burt David W

2010-04-01

110

Bioassessment of mercury, cadmium, polychlorinated biphenyls, and pesticides in the upper Mississippi River with zebra mussels (Dreissena polymorpha)  

Science.gov (United States)

Zebra mussels (Dreissena polymorpha) were sampled from artificial substrates deployed from May 30 to October 19, 1995, at 19 locks and dams from Minneapolis, MN, to Muscatine, IA. Analyses of composite tissue samples of zebra mussels (10-20-mm length) revealed accumulation of mercury(Hg), cadmium (Cd), and polychlorinated biphenyls (PCBs) during a 143-d exposure period. Concentrations of total Hg ranged from 2.6 to 6.1 ng/g wet weight and methylmercury (CH3Hg) from 1.0 to 3.3 ng/g wet weight. About 50% (range 30-70%) of the mean total Hg in zebra mussels was CH3Hg. Cadmium ranged from 76 to 213 ng/g wet weight. Concentrations of total PCBs (Aroclor 1254) in zebra mussels varied longitudinally (range 1000-7330 ng/g lipid weight), but the composition of PCB congeners (total of 21 measured) was similar throughout the river. Chlordane and dieldrin were the only two pesticides detected of the 15 analyzed. Zebra mussels are sentinels of contaminant bioavailability in the Upper Mississippi River and may be an important link in the trophic transfer of contaminants in the river because of their increasing importance in the diets of certain fish and waterfowl.

Cope, W. Gregory; Bartsch, Michelle R.; Rada, Ronald G.; Balogh, Steven J.; Rupprecht, John E.; Young, R. David; Johnson, D. Kent

1999-01-01

111

Using Digital Images of the Zebra Finch Song System as a Tool to Teach Organizational Effects of Steroid Hormones: A Free Downloadable Module  

Science.gov (United States)

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the…

Grisham, William; Schottler, Natalie A.; Beck McCauley, Lisa M.; Pham, Anh P.; Ruiz, Maureen L.; Fong, Michelle C.; Cui, Xinran

2011-01-01

112

Genome-wide annotation and analysis of zebra finch microRNA repertoire reveal sex-biased expression  

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Full Text Available Abstract Background MicroRNAs (miRNAs are small noncoding RNAs that regulate gene expression post-transcriptionally in a wide range of biological processes. The zebra finch (Taeniopygia guttata, an oscine songbird with characteristic learned vocal behavior, provides biologists a unique model system for studying vocal behavior, sexually dimorphic brain development and functions, and comparative genomics. Results We deep sequenced small RNA libraries made from the brain, heart, liver, and muscle tissues of adult male and female zebra finches. By mapping the sequence reads to the zebra finch genome and to known miRNAs in miRBase, we annotated a total of 193 miRNAs. Among them, 29 (15% are avian specific, including three novel zebra finch specific miRNAs. Many of the miRNAs exhibit sequence heterogeneity including length variations, untemplated terminal nucleotide additions, and internal substitution events occurring at the uridine nucleotide within a GGU motif. We also identified seven Z chromosome-encoded miRNAs. Among them, miR-2954, an avian specific miRNA, is expressed at significantly higher levels in males than in females in all tissues examined. Target prediction analysis reveals that miR-2954, but not other Z-linked miRNAs, preferentially targets Z chromosome-encoded genes, including several genes known to be expressed in a sexually dimorphic manner in the zebra finch brain. Conclusions Our genome-wide systematic analysis of mature sequences, genomic locations, evolutionary sequence conservation, and tissue expression profiles of the zebra finch miRNA repertoire provides a valuable resource to the research community. Our analysis also reveals a miRNA-mediated mechanism that potentially regulates sex-biased gene expression in avian species.

Luo Guan-Zheng

2012-12-01

113

Simple sequence repeats in zebra finch (Taeniopygia guttata expressed sequence tags: a new resource for evolutionary genetic studies of passerines  

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Full Text Available Abstract Background Passerines (perching birds are widely studied across many biological disciplines including ecology, population biology, neurobiology, behavioural ecology and evolutionary biology. However, understanding the molecular basis of relevant traits is hampered by the paucity of passerine genomics tools. Efforts to address this problem are underway, and the zebra finch (Taeniopygia guttata will be the first passerine to have its genome sequenced. Here we describe a bioinformatic analysis of zebra finch expressed sequence tag (EST Genbank entries. Results A total of 48,862 ESTs were downloaded from GenBank and assembled into contigs, representing an estimated 17,404 unique sequences. The unique sequence set contained 638 simple sequence repeats (SSRs or microsatellites of length ?20 bp and purity ?90% and 144 simple sequence repeats of length ?30 bp. A chromosomal location for the majority of SSRs was predicted by BLASTing against assembly 2.1 of the chicken genome sequence. The relative exonic location (5' untranslated region, coding region or 3' untranslated region was predicted for 218 of the SSRs, by BLAST search against the ENSEMBL chicken peptide database. Ten loci were examined for polymorphism in two zebra finch populations and two populations of a distantly related passerine, the house sparrow Passer domesticus. Linkage was confirmed for four loci that were predicted to reside on the passerine homologue of chicken chromosome 7. Conclusion We show that SSRs are abundant within zebra finch ESTs, and that their genomic location can be predicted from sequence similarity with the assembled chicken genome sequence. We demonstrate that a useful proportion of zebra finch EST-SSRs are likely to be polymorphic, and that they can be used to build a linkage map. Finally, we show that many zebra finch EST-SSRs are likely to be useful in evolutionary genetic studies of other passerines.

Birkhead Timothy R

2007-02-01

114

Diversidad malacológica en una comunidad de Arca zebra (Mollusca: Bivalviaen Chacopata, Estado Sucre, Venezuela  

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Full Text Available La diversidad malacológica de una comunidad submareal de Arca zebra se estudió, desde septiembre, 1990 hasta septiembre, 1991, en Chacopata, Estado Sucre, Venezuela. Se identificaron 40 especies (24 de bivalvos y 16 de gasterópodos. Los parámetros de diversidad en número de la comunidad fueron bajos (H` = 2.087 bits /ind., J` = 0.392, Simpson = 0.528 cuando se comparan con otros reportes de áreas tropicales. Los datos del número de individuos por especies con el rango conforman una línea recta ajustada por la serie logaritmica, con un índice de diversidad (a de 5.66. Las máximas diversidades mensuales se observaron en septiembre, 1990 (1.63 bits/ind. y julio, 1991 (1.60 bits/ind., la mínima ocurrió en junio, 1991 (0.52 bits/ind.. De las 40 especies identificadas, la pepitona, Arca zebra fue la especie dominante en número (68.87 % y en biomasa (72.34 %, seguida por Pinctada imbricata, Modiolus squamosus, Chama macerophyla y Anadara notabilis. Los gasterópodos predadores Phyllonotus pomum, Chicoreus brevifrons y Murex recurvirostris parecen tener relaciones tróficas con la especie dominante. La biomasa promedio total en peso húmedo con la concha (469.20 + 263 g m-2 es alta e indica que A. zebra, la especie dominante de rápido crecimiento, desempeña el papel más importante en la comunidad como un eficiente filtrador, que convierte el alimento planctónico en biomasa disponible, soportando una de las pesquerías más importantes de la región.The diversity of a subtidal epifaunal mollusk community was studied from September, 1990 to September, 1991 in Chacopata, Sucre State, Venezuela. There were 40 species (24 bivalves and 16 gastropods. The diversity indexes (H` = 2.087, J`=0.392, 1/D = 0.528 were low when compared with other tropical zones. Monthly diversity reached its maximum in September, 1990 (1.63 bits/ind. and July, 1991 (1.60 bits/ind.; minimum diversity occurred in June, 1991 (0.52 bits/ind.. A Log series model applied to species abundance data showed a straight line with a diversity index a of 5.56. Of 40 species identified, the turkeywing Arca zebra was dominant (69 % in number of individuals and 72 % of biomass followed by Pinctada imbricata, Modiolus squamosus, Chama macerophyla and Anadara notabilis. The predatory snails Phyllonotus pomum, Chicoreus brevifrons and Murex recurvirostris seemed to have trophic relationships with A. zebra. The total mean biomass in wet weight (469.20 + 263g m-2, shell included was high which indicates that A. zebra, a species with a rapid growth rate, occupies a central role in the assemblage as an efficient filter feeder that converts planktonic food into available biomass, supporting one of the most important fisheries in Venezuela.

Antulio S. Prieto

2001-06-01

115

Origin of Spanish invasion by the zebra mussel, Dreissena polymorpha (Pallas, 1771) revealed by amplified fragment length polymorphism (AFLP) fingerprinting  

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The zebra mussel, Dreissena polymorpha is an aquatic nuisance invasive species originally native to the Ponto-Caspian region where it is found in lakes and delta areas of large rivers draining into the Black and Caspian seas. The dispersal of D. polymorpha began at the end of the 18th century, at a time when shipping trade become increasingly important and many canals were built for linking different navigable river systems in Europe. Over the past 200 years, zebra mussels spread to most of t...

Rajagopal, S.; Pollux, B. J. A.; Peters, J. L.; Cremers, G.; Moon- Staay, S. Y.; Alen, T.; Eygensteyn, J.; Hoek, A. H. A. M.; Palau, A.; Vaate, A. B.; Velde, G.

2009-01-01

116

Current Status of Health and Safety Issues of Sodium/Metal Chloride (Zebra) Batteries  

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This report addresses environmental, health, and safety (EH&S) issues associated with sodium/ metal chloride batteries, in general, although most references to specific cell or battery types refer to units developed or being developed under the Zebra trademark. The report focuses on issues pertinent to sodium/metal chloride batteries and their constituent components; however, the fact that some ''issues'' arise from interaction between electric vehicle (EV) and battery design compels occasional discussion amid the context of EV vehicle design and operation. This approach has been chosen to provide a reasonably comprehensive account of the topic from a cell technology perspective and an applications perspective.

Trickett, D.

1998-12-15

117

Current Status of Health and Safety Issues of Sodium/Metal Chloride (Zebra) Batteries  

International Nuclear Information System (INIS)

This report addresses environmental, health, and safety (EH ampersand S) issues associated with sodium/ metal chloride batteries, in general, although most references to specific cell or battery types refer to units developed or being developed under the Zebra trademark. The report focuses on issues pertinent to sodium/metal chloride batteries and their constituent components; however, the fact that some ''issues'' arise from interaction between electric vehicle (EV) and battery design com- pels occasional discussion amid the context of EV vehicle design and operation. This approach has been chosen to provide a reasonably comprehensive account of the topic from a cell technology perspective and an applications perspective

118

Oscillating magnetic field disrupts magnetic orientation in Zebra finches, Taeniopygia guttata  

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Full Text Available Abstract Background Zebra finches can be trained to use the geomagnetic field as a directional cue for short distance orientation. The physical mechanisms underlying the primary processes of magnetoreception are, however, largely unknown. Two hypotheses of how birds perceive magnetic information are mainly discussed, one dealing with modulation of radical pair processes in retinal structures, the other assuming that iron deposits in the upper beak of the birds are involved. Oscillating magnetic fields in the MHz range disturb radical pair mechanisms but do not affect magnetic particles. Thus, application of such oscillating fields in behavioral experiments can be used as a diagnostic tool to decide between the two alternatives. Methods In a setup that eliminates all directional cues except the geomagnetic field zebra finches were trained to search for food in the magnetic north/south axis. The birds were then tested for orientation performance in two magnetic conditions. In condition 1 the horizontal component of the geomagnetic field was shifted by 90 degrees using a helmholtz coil. In condition 2 a high frequently oscillating field (1.156 MHz was applied in addition to the shifted field. Another group of birds was trained to solve the orientation task, but with visual landmarks as directional cue. The birds were then tested for their orientation performance in the same magnetic conditions as applied for the first experiment. Results The zebra finches could be trained successfully to orient in the geomagnetic field for food search in the north/south axis. They were also well oriented in test condition 1, with the magnetic field shifted horizontally by 90 degrees. In contrast, when the oscillating field was added, the directional choices during food search were randomly distributed. Birds that were trained to visually guided orientation showed no difference of orientation performance in the two magnetic conditions. Conclusion The results indicate that zebra finches use a receptor that bases on radical pair processes for sensing the direction of the earth magnetic field in this short distance orientation behavior.

Wiltschko Wolfgang

2009-10-01

119

Autoradiographic localization of nicotinic acetylcholine receptors in the brain of the zebra finch (Poephila guttata)  

International Nuclear Information System (INIS)

We have localized nicotinic acetylcholine receptors in the zebra finch brain by using three 125I-labelled ligands: alpha bungarotoxin and two monoclonal antibodies to neuronal nicotinic receptors. Unfixed brains from intact adult male and female zebra finches were prepared for in vitro autoradiography. Low-resolution film autoradiograms and high-resolution emulsion autoradiograms were prepared for each of the three ligands. The major brain structures that bind all three of the ligands are hippocampus; hyperstriatum dorsalis; hyperstriatum ventralis; nucleus lentiformis mesencephali; nucleus pretectalis, some layers of the optic tectum; nucleus mesencephalicus lateralis; pars dorsalis; locus ceruleus; and all cranial motor nuclei except nucleus nervi hypoglossi. The major structures labelled only by [125I]-alpha bungarotoxin binding included hyperstriatum accessorium and the nuclei: preopticus medialis, medialis hypothalami posterioris, semilunaris, olivarius inferior, and the periventricular organ. Of the song control nuclei, nucleus magnocellularis of the anterior neostriatum; hyperstriatum ventralis, pars caudalis; nucleus intercollicularis; and nucleus hypoglossus were labelled. The binding patterns of the two antibodies were similar to one another but not identical. Both labelled nucleus spiriformis lateralis and nucleus geniculatus lateralis, pars ventralis especially heavily and also labelled the nucleus habenula medialis; nucleus subpretectalis; nucleus isthmi, pars magnocellularis; nucleus reticularis gigantocellularis; nucleus reticularis lateralis; nucleus tractus solitarii; nucleus vestibularis dorsolateralis; nucleus vestibularis lateralis; nucleus descendens nervi trigemini; and the deep cerebellar nuclei

120

Sex differences of excitatory synaptic transmission in RA projection neurons of adult zebra finches.  

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Zebra finches are ideal animals to investigate sex difference in songbirds. Only males can sing. The brain nuclei controlling song learning and production in males are considerably larger than in females. The robust nucleus of the arcopallium (RA) is a premotor nucleus, playing a key role in controlling singing. RA receives denser synapse inputs in males than in females. Sex differences of excitatory synaptic transmission in the RA projection neurons (PNs) have not been reported. In the present study, using whole-cell voltage-clamp recording, spontaneous EPSCs (sEPSCs) and miniature EPSCs (mEPSCs) of RA PNs in the intact males and females were recorded. The average frequency and amplitude of sEPSCs/mEPSCs in the intact males were higher than females. The half-width and decay time of sEPSCs/mEPSCs in the intact males were longer than females. In order to verify whether these sex differences related to sex steroids, males were castrated. The average frequency of sEPSCs/mEPSCs in castrated males was lower than intact males and was similar to in females; the amplitude was not changed after castrating. These results demonstrate the sexually dimorphic of the excitatory synaptic transmission in the RA PNs, the RA PNs in males receive more excitatory synaptic transmission and these sex differences were partly affected by sex hormones. These findings contribute to further illuminate the neural mechanisms under the sexually dimorphism in song production of adult zebra finches. PMID:25220700

Wang, Songhua; Meng, Wei; Liu, Shaoyi; Liao, Congshu; Huang, Qingyao; Li, Dongfeng

2014-10-17

 
 
 
 
121

Familial differences in the effects of mercury on reproduction in zebra finches  

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Ecotoxicologists often implicitly assume that populations are homogenous entities in which all individuals have similar responses to a contaminant. However, genetically variable responses occur within populations. This variation can be visualized using dose–response curves of genetically related groups, similar to the way that evolutionary biologists construct reaction norms. We assessed the variation in reproductive success of full-sibling families of captive zebra finches (Taeniopygia guttata) experimentally exposed to methylmercury. We found significant variation among families in the effects of methylmercury on several reproductive parameters. This variation suggests that there may be strong responses to selection for resistant genotypes in contaminated areas. This has important implications for the evolution of tolerance as well as risk assessment and wildlife conservation efforts on sites with legacy contamination. -- Highlights: •Dose-response curves can visualize genetic differences in response to pollutants. •Families of zebra finch respond differently to mercury contamination. •Differences in reproductive success can lead to selection for resistant genotypes. •Resistance to contamination has implications for risk assessment and conservation. -- Genetic variation in response to contaminants can lead to adaptation on long-term contaminated sites, with implications for risk assessment and conservation of impacted popula

122

Sexual differentiation of the zebra finch song system: potential roles for sex chromosome genes  

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Full Text Available Abstract Background Recent evidence suggests that some sex differences in brain and behavior might result from direct genetic effects, and not solely the result of the organizational effects of steroid hormones. The present study examined the potential role for sex-biased gene expression during development of sexually dimorphic singing behavior and associated song nuclei in juvenile zebra finches. Results A microarray screen revealed more than 2400 putative genes (with a false discovery rate less than 0.05 exhibiting sex differences in the telencephalon of developing zebra finches. Increased expression in males was confirmed in 12 of 20 by qPCR using cDNA from the whole telencephalon; all of these appeared to be located on the Z sex chromosome. Six of the genes also showed increased expression in one or more of the song control nuclei of males at post-hatching day 25. Although the function of half of the genes is presently unknown, we have identified three as: 17-beta-hydroxysteroid dehydrogenase type IV, methylcrotonyl-CoA carboxylase, and sorting nexin 2. Conclusion The data suggest potential influences of these genes in song learning and/or masculinization of song system morphology, both of which are occurring at this developmental stage.

Clayton David F

2009-03-01

123

Parasitism can be a confounding factor in assessing the response of zebra mussels to water contamination  

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Biological responses measured in aquatic organisms to monitor environmental pollution could be also affected by different biotic and abiotic factors. Among these environmental factors, parasitism has often been neglected even if infection by parasites is very frequent. In the present field investigation, the parasite infra-communities and zebra mussel biological responses were studied up- and downstream a waste water treatment plant in northeast France. In both sites, mussels were infected by ciliates and/or intracellular bacteria, but prevalence rates and infection intensities were different according to the habitat. Concerning the biological responses differences were observed related to the site quality and the infection status. Parasitism affects both systems but seemed to depend mainly on environmental conditions. The influence of parasites is not constant, but remains important to consider it as a potential confounding factor in ecotoxicological studies. This study also emphasizes the interesting use of integrative indexes to synthesize data set. Highlights: ? Study of potential bias associated with the use of infected zebra mussels in ecotoxicological studies. ? Presence of infected mussels on banks and channels, up- and downstream a waste water treatment plant. ? Parasitism influence on biological responses dependent of mussel population history. ? Integrative index, an interesting tool to synthesize the set of biological data. - Parasitism influence on the host physiology would be strongly dependent on environmental conditions but remains a potential confounding factor in ecotoxicological studies.

124

Digital Atlas of the Zebra Finch (Taeniopygia guttata) Brain: a High Resolution Photo Atlas  

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We describe a set of new comprehensive, high-quality, high-resolution digital images of histological sections from the brain of male zebra finches (Taeniopygia guttata), and make them publicly available through an interactive website (http://zebrafinch.brainarchitecture.org/). These images provide a basis for the production of a dimensionally accurate and detailed digital non-stereotaxic atlas. Nissl- and myelin-stained brain sections are provided in the transverse, sagittal, and horizontal planes, with the transverse plane approximating the more traditional Frankfurt Plane. In addition, a separate set of brain sections in this same plane is stained for tyrosine hydroxylase, revealing the distribution of catecholaminergic neurons (dopaminergic, noradrenergic, and adrenergic) in the songbird brain. For a subset of sagittal sections we have also prepared a corresponding set of drawings, defining and annotating various nuclei, fields, and fiber tracts that are visible under Nissl and myelin staining. This atlas of the zebra finch brain is expected to become an important tool for birdsong research and comparative studies of brain organization and evolution. PMID:23896990

Karten, Harvey J.; Brzozowska-Prechtl, Agnieszka; Lovell, Peter V.; Tang, Daniel D.; Mello, Claudio V.; Wang, Haibin; Mitra, Partha P.

2014-01-01

125

Habitat shift in invading species: Zebra and quagga mussel population characteristics on shallow soft substrates  

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Unexpected habitat innovations among invading species are illustrated by the expansion of dreissenid mussels across sedimentary environments in shallow water unlike the hard substrates where they are conventionally known. In this note, records of population characteristics of invading zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels from 1994 through 1998 are reported from shallow (less than 20 m) sedimentary habitats in western Lake Erie. Haphazard SCUBA collections of these invading species indicated that combined densities of zebra and quagga mussels ranged from 0 to 32,500 individuals per square meter between 1994 and 1998, with D. polymorpha comprising 75-100% of the assemblages. These mixed mussel populations, which were attached by byssal threads to each other and underlying sand-grain sediments, had size-frequency distributions that were typical of colonizing populations on hard substrates. Moreover, the presence of two mussel cohorts within the 1994 samples indicated that these species began expanding onto soft substrates not later than 1992, within 4 years of their initial invasion in western Lake Erie. Such historical data provide baselines for interpreting adaptive innovations, ecological interactions and habitat shifts among the two invading dreissenid mussel species in North America.

Berkman, P.A.; Garton, D.W.; Haltuch, M.A.; Kennedy, G.W.; Febo, L.R.

2000-01-01

126

Differences in metal sequestration between zebra mussels from clean and polluted field locations  

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Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular fractions with increasing whole tissue concentrations. However, metal concentrations in the sensitive fractions did not increase to the same extent as metal concentrations in whole tissues. In more polluted mussels the contribution of MRG and MT became more important. Nevertheless, metal detoxification was not sufficient to prevent metal binding to heat-sensitive low molecular weight proteins (HDP fraction). Finally we found an indication that metal detoxification was influenced by the condition of the zebra mussels. MT content could be explained for up to 83% by variations in Zn concentration and physiological condition of the mussels.

Voets, Judith [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Redeker, Erik Steen [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Institute for Materials Research, Chemistry Division, Hasselt University, Agoralaan Building D G1-36, B 3590 Diepenbeek (Belgium); Blust, Ronny [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Bervoets, Lieven, E-mail: Lieven.bervoets@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

2009-06-04

127

Developmental plasticity, modularity, and heterochrony during the phylotypic stage of the zebra fish, Danio rerio.  

Science.gov (United States)

We studied early embryonic development of zebra fish and tested if changes in the external raising conditions could elicit phenotypic changes during the phylotypic stage which, classically, is considered as a conserved embryonic stage. In particular, we tested for internal constraints, plasticity, and heterochrony during the early embryonic development. Our tested hypotheses predict (i) no change associated with developmental stability/internal constraints, (ii) change of the rate of development associated with developmental flexibility, and (iii) heterochronic disruption of developmental pattern associated with a modular organization of the embryo. We measured 14 traits of embryos raised in different conditions (temperature, salinity, oxygen concentration). The results of our study show that zebra fish embryos respond flexibly to changes in external parameters even during the conserved "phylotypic stage." It also showed that internal constraints canalize early development when exposed to moderate external challenges. Hypoxic conditions, however, elicited a heterochronic delay of the onset of the development of the Anlagen of the eye and the otic vesicle from the remaining embryo. Therefore, we concluded that the eye and the otic vesicle are modules that may develop, to a certain degree, independently of the rest of the embryo. Because these modules become recognizable only under specific raising conditions, we suggest that the modularization acts as buffering mechanism against extreme developmental deviations. Our results provide support to the idea that modularity is present during the phylotypic stage, but it is not effective under normal conditions. PMID:19757482

Schmidt, Kai; Starck, J Matthias

2010-03-15

128

Autoradiographic localization of nicotinic acetylcholine receptors in the brain of the zebra finch (Poephila guttata)  

Energy Technology Data Exchange (ETDEWEB)

We have localized nicotinic acetylcholine receptors in the zebra finch brain by using three 125I-labelled ligands: alpha bungarotoxin and two monoclonal antibodies to neuronal nicotinic receptors. Unfixed brains from intact adult male and female zebra finches were prepared for in vitro autoradiography. Low-resolution film autoradiograms and high-resolution emulsion autoradiograms were prepared for each of the three ligands. The major brain structures that bind all three of the ligands are hippocampus; hyperstriatum dorsalis; hyperstriatum ventralis; nucleus lentiformis mesencephali; nucleus pretectalis, some layers of the optic tectum; nucleus mesencephalicus lateralis; pars dorsalis; locus ceruleus; and all cranial motor nuclei except nucleus nervi hypoglossi. The major structures labelled only by (125I)-alpha bungarotoxin binding included hyperstriatum accessorium and the nuclei: preopticus medialis, medialis hypothalami posterioris, semilunaris, olivarius inferior, and the periventricular organ. Of the song control nuclei, nucleus magnocellularis of the anterior neostriatum; hyperstriatum ventralis, pars caudalis; nucleus intercollicularis; and nucleus hypoglossus were labelled. The binding patterns of the two antibodies were similar to one another but not identical. Both labelled nucleus spiriformis lateralis and nucleus geniculatus lateralis, pars ventralis especially heavily and also labelled the nucleus habenula medialis; nucleus subpretectalis; nucleus isthmi, pars magnocellularis; nucleus reticularis gigantocellularis; nucleus reticularis lateralis; nucleus tractus solitarii; nucleus vestibularis dorsolateralis; nucleus vestibularis lateralis; nucleus descendens nervi trigemini; and the deep cerebellar nuclei.

Watson, J.T.; Adkins-Regan, E.; Whiting, P.; Lindstrom, J.M.; Podleski, T.R.

1988-08-08

129

Dose-dependent uptake, elimination, and toxicity of monosodium methanearsonate in adult zebra finches (Taeniopygia guttata).  

Science.gov (United States)

Monosodium methanearsonate (MSMA), an arsenic-based pesticide, has been used for the past 10 years in attempts to suppress mountain pine beetle (Dendroctonus ponderosae) outbreaks in British Columbia, Canada. Previous studies have shown that cavity nesting forest birds such as woodpeckers forage and breed in MSMA treated pine stands. Here we examined the effects of MSMA in the laboratory using the zebra finch (Taeniopygia guttata), with the objective to examine tissue distribution and sublethal toxic effects in a model avian species. Zebra finches were exposed to this pesticide at doses similar to those found in bark beetle samples from MSMA stands of trees treated in the southern interior of British Columbia (8, 24, and 72 microg/g/d and a control group). Results showed high excretion (>90%) of arsenic in all dose groups, as well as dose-dependent trends in accumulation of arsenic in the blood (p < 0.001) and specific tissues. Monomethylarsonic acid, MMA (V), was the predominant form of arsenic in the blood plasma. Dimethylarsinic acid was the major form of arsenic found in the liver (83%) and kidney (61%) tissues. The brain tissue contained primarily the MMA (V) form (57%). Significant weight loss occurred in the two highest dose groups (p < 0.05). Birds in the highest dose group lost up to 15% of initial body mass. PMID:17988177

Albert, Courtney A; Williams, Tony D; Morrissey, Christy A; Lai, Vivian W M; Cullen, William R; Elliott, John E

2008-03-01

130

Sex bias and dosage compensation in the zebra finch versus chicken genomes: general and specialized patterns among birds.  

Science.gov (United States)

We compared global patterns of gene expression between two bird species, the chicken and zebra finch, with regard to sex bias of autosomal versus Z chromosome genes, dosage compensation, and evolution of sex bias. Both species appear to lack a Z chromosome-wide mechanism of dosage compensation, because both have a similar pattern of significantly higher expression of Z genes in males relative to females. Unlike the chicken Z chromosome, which has female-specific expression of the noncoding RNA MHM (male hypermethylated) and acetylation of histone 4 lysine 16 (H4K16) near MHM, the zebra finch Z chromosome appears to lack the MHM sequence and acetylation of H4K16. The zebra finch also does not show the reduced male-to-female (M:F) ratio of gene expression near MHM similar to that found in the chicken. Although the M:F ratios of Z chromosome gene expression are similar across tissues and ages within each species, they differ between the two species. Z genes showing the greatest species difference in M:F ratio were concentrated near the MHM region of the chicken Z chromosome. This study shows that the zebra finch differs from the chicken because it lacks a specialized region of greater dosage compensation along the Z chromosome, and shows other differences in sex bias. These patterns suggest that different avian taxa may have evolved specific compensatory mechanisms. PMID:20357053

Itoh, Yuichiro; Replogle, Kirstin; Kim, Yong-Hwan; Wade, Juli; Clayton, David F; Arnold, Arthur P

2010-04-01

131

Zebra tape identification for the instantaneous angular speed computation and angular resampling of motorbike valve train measurements  

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An experimental test campaign was performed on the valve train of a racing motorbike engine in order to get insight into the dynamic of the system. In particular the valve motion was acquired in cold test conditions by means of a laser vibrometer able to acquire displacement and velocity signals. The valve time-dependent measurements needed to be referred to the camshaft angular position in order to analyse the data in the angular domain, as usually done for rotating machines. To this purpose the camshaft was fitted with a zebra tape whose dark and light stripes were tracked by means of an optical probe. Unfortunately, both manufacturing and mounting imperfections of the employed zebra tape, resulting in stripes with slightly different widths, precluded the possibility to directly obtain the correct relationship between camshaft angular position and time. In order to overcome this problem, the identification of the zebra tape was performed by means of the original and practical procedure that is the focus of the present paper. The method consists of three main steps: namely, an ad-hoc test corresponding to special operating conditions, the computation of the instantaneous angular speed, and the final association of the stripes with the corresponding shaft angular position. The results reported in the paper demonstrate the suitability of the simple procedure for the zebra tape identification performed with the final purpose to implement a computed order tracking technique for the data analysis.

Rivola, Alessandro; Troncossi, Marco

2014-02-01

132

Hudson River Unionids and Zebra Mussels: The Beginning of the End or the End of the Beginning?  

Science.gov (United States)

The invasion of the Hudson River estuary by zebra mussels was followed by steep declines (77 to >99.7%) in populations of all species of native bivalves between 1992 and 1999. Body condition of all unionids, and growth and recruitment of young unionids also declined significantly. Declines in population size and body condition were correlated primarily with the filtration rate of the zebra mussel population, not with fouling of native bivalves by zebra mussels. Samples taken since 2000, however, have shown that populations of all 4 common native bivalves have stabilized or even recovered, although the zebra mussel population has not declined. The mechanisms underlying this apparent reversal of fortune are not clear: recruitment and growth of young mussels have showed limited recovery, but body condition of adults has not. We found no evidence that spatial refuges contributed to this reversal of population declines. Simple statistical models project now that native bivalves may persist at population densities about an order of magnitude below their pre-invasion densities.

Strayer, D. L.; Malcom, H. M.

2005-05-01

133

Song exposure regulates known and novel microRNAs in the zebra finch auditory forebrain  

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Full Text Available Abstract Background In an important model for neuroscience, songbirds learn to discriminate songs they hear during tape-recorded playbacks, as demonstrated by song-specific habituation of both behavioral and neurogenomic responses in the auditory forebrain. We hypothesized that microRNAs (miRNAs or miRs may participate in the changing pattern of gene expression induced by song exposure. To test this, we used massively parallel Illumina sequencing to analyse small RNAs from auditory forebrain of adult zebra finches exposed to tape-recorded birdsong or silence. Results In the auditory forebrain, we identified 121 known miRNAs conserved in other vertebrates. We also identified 34 novel miRNAs that do not align to human or chicken genomes. Five conserved miRNAs showed significant and consistent changes in copy number after song exposure across three biological replications of the song-silence comparison, with two increasing (tgu-miR-25, tgu-miR-192 and three decreasing (tgu-miR-92, tgu-miR-124, tgu-miR-129-5p. We also detected a locus on the Z sex chromosome that produces three different novel miRNAs, with supporting evidence from Northern blot and TaqMan qPCR assays for differential expression in males and females and in response to song playbacks. One of these, tgu-miR-2954-3p, is predicted (by TargetScan to regulate eight song-responsive mRNAs that all have functions in cellular proliferation and neuronal differentiation. Conclusions The experience of hearing another bird singing alters the profile of miRNAs in the auditory forebrain of zebra finches. The response involves both known conserved miRNAs and novel miRNAs described so far only in the zebra finch, including a novel sex-linked, song-responsive miRNA. These results indicate that miRNAs are likely to contribute to the unique behavioural biology of learned song communication in songbirds.

Kim Jong H

2011-05-01

134

Temporal variation in zebra mussel (Dreissena polymorpha) density structure the benthic food web and community composition on hard substrates in Lake Constance, Germany  

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Invasive species often influence existing biocenoses by altering their environment or facilitating the ecology of other species. Here we combined stable isotope analysis with quantitative benthic community sampling to investigate temporal variation in the influence of biodeposition of organic material (biodeposits) by the zebra mussel (Dreissena polymorpha) on the benthic food web in hard substrate habitats of Lake Constance, Germany. The accumulation of organic material excreted by zebra mus...

Gergs, Rene?; Grey, Jonathan; Rothhaupt, Karl-otto

2011-01-01

135

The Origin of a “Zebra” Chromosome in Wheat Suggests Nonhomologous Recombination as a Novel Mechanism for New Chromosome Evolution and Step Changes in Chromosome Number  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An alloplasmic wheat line, TA5536, with the “zebra” chromosome z5A was isolated from an Elymus trachycaulus/Triticum aestivum backcross derivative. This chromosome was named “zebra” because of its striped genomic in situ hybridization pattern. Its origin was traced to nonhomologous chromosome 5A of wheat and 1Ht of Elymus; four chromatin segments were derived from chromosome 1Ht and five chromatin segments including the centromere from 5A. In this study, our objective was to determine...

Zhang, Peng; Li, Wanlong; Friebe, Bernd; Gill, Bikram S.

2008-01-01

136

New records of 43 spider species from the Mountain Zebra National Park, South Africa (Arachnida: Araneae  

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Full Text Available This study forms part of the South African National Survey of Arachnida (SANSA, initiated in 1997 with the main aim to create an inventory of the arachnid fauna of South Africa (Dippenaar-Schoeman & Craemer 2000. One of the objectives of SANSA is to assess the number of arachnid species presently protected in conserved areas in the country. Check lists of spiders are now available for three national parks, three nature reserves and a conservancy. These areas include: Mountain Zebra National Park (Dippenaar-Schoeman 1988; Karoo National Park (Dippenaar-Schoeman et al. 1999; Kruger National Park (Dippenaar- Schoeman & Leroy 2002; Roodeplaatdam Nature Reserve (Dippenaar-Schoeman et al. 1989; Makelali Nature Reserve (Whitmore et al. 2001, 2002; Swartberg Nature Reserve (Dippenaar-Schoeman et al. 2005; and the Soutpansberg Conservancy (Foord et al. 2002.

A.S. Dippenaar-Schoeman

2006-12-01

137

Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes.  

Science.gov (United States)

Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. PMID:17561323

Riva, Consuelo; Binelli, Andrea; Provini, Alfredo

2008-02-01

138

Infestation of Monroe Power Plant by the zebra mussel (dreissena polymorpha)  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that since introduction into the lower Great Lakes, the density of zebra mussels at Monroe Power Plant in western Lake Erie has increased dramatically. In fall 1988 densities in the intake canal were less than 50 per sq. meter but increased to over 700,000 per sq meter by fall 1989. Intake structures and associated equipment are covered by a layer of mussels 5-8 cm thick. High densities have fouled trash bars, main steam condensors, heat exchangers and low pressure service water systems. Blockage of main stream condensors is 10-20 percent with most of blockage caused by druses (clusters) that slough from intake structures. To minimize operational problems, hydroblasting has been used to remove mussels from the most vulnerable components.

Kovalak, W.P.; Longton, G.D.; Smithee, R.D. (Detroit Edison Co., MI (United States))

1990-01-01

139

QUASI-PERIODIC WIGGLES OF MICROWAVE ZEBRA STRUCTURES IN A SOLAR FLARE  

International Nuclear Information System (INIS)

Quasi-periodic wiggles of microwave zebra pattern (ZP) structures with periods ranging from about 0.5 s to 1.5 s are found in an X-class solar flare on 2006 December 13 at the 2.6-3.8 GHz with the Chinese Solar Broadband Radio Spectrometer (SBRS/Huairou). Periodogram and correlation analysis show that the wiggles have two to three significant periodicities and are almost in phase between stripes at different frequencies. The Alfvén speed estimated from the ZP structures is about 700 km s–1. We find the spatial size of the wave-guiding plasma structure to be about 1 Mm with a detected period of about 1 s. This suggests that the ZP wiggles can be associated with the fast magnetoacoustic oscillations in the flaring active region. The lack of a significant phase shift between wiggles of different stripes suggests that the ZP wiggles are caused by a standing sausage oscillation

140

Changes in Benthic Invertebrate Communities During the Introduction of Zebra Mussels Into an Impounded Michigan River  

Science.gov (United States)

Zebra mussels (Dreissena polymorpha, ZM) were introduced into the Croton impoundment on the Muskegon River, MI, sometime during the late 1990s, and subsequently colonized downstream. We evaluated changes in invertebrate communities in the Muskegon River during ZM colonization. ZM were not found in benthic samples collected during 1998-1999 but densities reached 12,000 m-2 and 26,000 m-2 in 2000 and 2001 respectively, immediately below the Croton impoundment. ZM densities remained relatively low (Chironomidae were uncommon in 1998-99 samples but were numerically dominant in 2000 and 2001 averaging 16525 m-2 over both years. Data from 2003 indicated that ZM remove 32% of suspended Chl. a in the first 500 m below Croton Dam. Thus, ZM may affect benthic invertebrate communities in impounded river systems by redistributing particulate organic matter within the system.

Luttenton, M.; Godby, N.; Rutherford, E.; Vankampen, S.

2005-05-01

 
 
 
 
141

Canal construction destroys the barrier between major European invasion lineages of the zebra mussel.  

Science.gov (United States)

Since the mid-1980s the zebra mussel, Dreissena polymorpha, Pallas 1771, has become the protagonist of a spectacular freshwater invasion in North America due to its large economic and biological impact. Several genetic studies on American populations have failed to detect any large-scale geographical patterns. In western Europe, where D. polymorpha has been a classical invader from the Pontocaspian since the early 19th century, the situation is strikingly different. Here, we show with genetic markers that two major western European invasion lineages with lowered genetic variability within and among populations can be discriminated. These two invasion lineages correspond with two separate navigable waterways to western Europe. We found a rapid and asymmetrical genetic interchange of the two invasion lines after the construction of the Main-Danube canal in 1992, which interconnected the two waterways across the main watershed. PMID:12061957

Müller, Jakob C; Hidde, Dennis; Seitz, Alfred

2002-06-01

142

The basic unit of the imaging plane of the ZEBRA low energy gamma ray telescope  

Energy Technology Data Exchange (ETDEWEB)

The mechanical, electrical, and performance characteristics of one element of the ZEBRA telescope's position sensitive detection plane are presented. One unit comprises a NaI (T1) bar 55 x 5, 8 x 5 cm thick and two photomultiplier tubes one mounted on each end. The surface of the bar has been treated to enhance the exponential attenuation of the scintillation light produced by an event. The signal from the two tubes are taken in coincidence and, by the application of two simple algorithms, the energy and position of the event along the bar can be calculated. The tubes are powered by two programmable low consumption high tension supplies. Their digital control makes automatic gain correction feasible during the flight.

Boella, G.; Bussini, A.; Butler, R.C.; Caroll, E.; Caralambous, P.M.; Dean, A.J.; Di Cocco, G.; Donati, S.; Graham, G.; Holder, S.M.

1986-02-01

143

Quagga and zebra mussel risk via veliger transfer by overland hauled boats  

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Full Text Available Invasive quagga and zebra mussels (Dreissena rostriformis bugensis and Dreissena polymorpha, respectively pose a great threat to USwaters. Recreational boats constitute a significant risk for spreading the organisms. Recreational boats circulate large amounts of raw waterwhen in use, and if not drained and dried correctly can transport many mussel larvae, called veligers. Veligers experience very high mortality rates; however, the number of potentially transported veligers can be a serious risk to non-infested bodies of water, especially if multiple boats are involved. The risk of veliger transport was calculated for Lake Mead and Lake Michigan using boat capacities for water circulation and specific veliger density data. Results illustrate the importance of draining, drying, and/or decontaminating recreational boats after use.

Larry B. Dalton

2013-04-01

144

QUASI-PERIODIC WIGGLES OF MICROWAVE ZEBRA STRUCTURES IN A SOLAR FLARE  

Energy Technology Data Exchange (ETDEWEB)

Quasi-periodic wiggles of microwave zebra pattern (ZP) structures with periods ranging from about 0.5 s to 1.5 s are found in an X-class solar flare on 2006 December 13 at the 2.6-3.8 GHz with the Chinese Solar Broadband Radio Spectrometer (SBRS/Huairou). Periodogram and correlation analysis show that the wiggles have two to three significant periodicities and are almost in phase between stripes at different frequencies. The Alfvén speed estimated from the ZP structures is about 700 km s{sup –1}. We find the spatial size of the wave-guiding plasma structure to be about 1 Mm with a detected period of about 1 s. This suggests that the ZP wiggles can be associated with the fast magnetoacoustic oscillations in the flaring active region. The lack of a significant phase shift between wiggles of different stripes suggests that the ZP wiggles are caused by a standing sausage oscillation.

Yu, Sijie; Tan, Baolin; Yan, Yihua [Key Laboratory of Solar Activity, National Astronomical Observatories Chinese Academy of Sciences, Beijing 100012 (China); Nakariakov, V. M.; Selzer, L. A., E-mail: sjyu@nao.cas.cn [Centre for Fusion, Space and Astrophysics, Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom)

2013-11-10

145

First Report of Coccidiosis and Gizzard Erosion in a Zebra Finch (Taeniopygia guttata of Iran  

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Full Text Available Coccidiosis and gizzard erosion are rare conditions in cage bird. A male zebra finch was presented with a history of watery diarrhea, anorexia, ruffled feathers, weight loss, and lethargy and died finally. Gross necropsy revealed small areas of erosions and hemorrhages on the gizzard wall. The intestine was oedematous. The spleen appeared pale and small. The testes were asymmetric.Histologically, necrosis of mucosal layer with infiltration of inflammatory cells observed in cecum. Eimeria stages were detected in the enterocytes. In Gizzard, hemorrhage and ulceration of mucosal layer with infiltration of polymorphonuclear cells in to the underlying mucosa were seen. In hepatic tissue, mild focal necrosis with mononuclear cells infiltration was seen. The disease was diagnosed as coccidiosis and gizzard erosion.

Moini, M.

2012-06-01

146

A Very Small and Super Strong Zebra Pattern Burst at the Beginning of a Solar Flare  

CERN Document Server

Microwave emission with spectral zebra pattern structures (ZPs) is observed frequently in solar flares and the Crab pulsar. The previous observations show that ZP is only a structure overlapped on the underlying broadband continuum with slight increments and decrements. This work reports an extremely unusual strong ZP burst occurring just at the beginning of a solar flare observed simultaneously by two radio telescopes located in China and Czech Republic and by the extreme ultraviolet (EUV) telescope on board NASA's satellite Solar Dynamics Observatory on 2013 April 11. It is a very short and super strong explosion whose intensity exceeds several times that of the underlying flaring broadband continuum emission, lasting for just 18 s. EUV images show that the flare starts from several small flare bursting points (FBPs). There is a sudden EUV flash with extra enhancement in one of these FBPs during the ZP burst. Analysis indicates that the ZP burst accompanying EUV flash is an unusual explosion revealing a str...

Tan, Baolin; Zhang, Yin; Huang, Jing; Meszarosova, Hana; Karlicky, Marian; Yan, Yihua

2014-01-01

147

An experimental test of condition-dependent male and female mate choice in zebra finches.  

Science.gov (United States)

In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences), sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology). While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study. PMID:21901147

Holveck, Marie-Jeanne; Geberzahn, Nicole; Riebel, Katharina

2011-01-01

148

Lessons from a transplantation of zebra mussels into a small urban river: An integrated ecotoxicological assessment.  

Science.gov (United States)

It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro-pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008. For two months, mussels and water samples were collected from two sites every two weeks and analyzed for metal and PAH content as well as water physicochemical parameters. Diffusive gradients in thin film (DGT) were also used to assess levels of labile metals. Exposure of mussels to contaminants and potential impact were evaluated using physiological indices and various biomarkers including condition index (CI), defense mechanisms (glutathione-S-transferase: GST), digestive enzymes (amylase and cellulase) and genotoxicity (micronucleus test: MN and comet assay: CA). For most contaminants, the water contamination was significantly higher downstream. Bioaccumulation in zebra mussels was related to water contamination in the framework of the biodynamic model, which allowed us to take into account the biological dilution that was caused by the growth of soft tissue downstream. Thus, metal influxes were on average two times higher downstream than upstream in particular for Zn, Cr, Cu and Cd. Significant differences in condition index were observed (final CI was 0.42 ± 0.03 downstream and 0.31 ± 0.03 upstream) reflecting a better food availability downstream. Moreover a significant decrease of GST activity and digestive enzymes activity in the cristalline style was observed downstream. Interpreting this decrease requires considering not only micro-pollution but also the trophic status related to the water's physicochemistry. The MN test and the CA on gill cells highlighted genotoxicity in mussels transplanted downstream compared to upstream. PMID:20549621

Bourgeault, A; Gourlay-Francé, C; Vincent-Hubert, F; Palais, F; Geffard, A; Biagianti-Risbourg, S; Pain-Devin, S; Tusseau-Vuillemin, M-H

2010-10-01

149

Developmental variability during early embryonic development of zebra fish, Danio rerio.  

Science.gov (United States)

Early vertebrate embryos pass through a period of remarkable morphological similarity. Possible causes for such similarity of early embryos include modularity, developmental constraints, stabilizing selection, canalization, and exhausted genetic variability. Supposedly, each process creates different patterns of variation and covariation of embryonic traits. We study the patterns of variation of the embryonic phenotype to test ideas about possible evolutionary mechanisms shaping the early embryonic development. We use the zebra fish, Danio rerio, as a model organism and apply repeated measures of individual embryos to study temporal changes of phenotypic variability during development. In particular, we are looking at the embryonic development from 12 hours post fertilization until 27 hours post fertilization. During this time period, the development of individual embryos is documented at hourly intervals. We measured maximum diameter of the eye, length of embryo, number of somites, inclination of somites, and the yolk size (as a maternal effect). The coefficient of variation (CV) was used as a measure of variability that was independent of size. We used a principal component analysis for analysis of morphological integration. The experimental setup kept environment x genotype interactions constant. Nongenetic parental contributions had no significant effects on interindividual variability. Thus all observed phenotypic variation was based on additive genetic variance and error variance. The average CV declined from 14% to 7.7%. The decline of the CV was in particular expressed during 15-19 h post fertilization and occurred in association with multiple correlations among embryonic traits and a relatively high degree of morphological integration. We suggest that internal constraints determine the patterns of variability during early embryonic development of zebra fish. PMID:15580642

Irmler, Ingo; Schmidt, Kai; Starck, J Matthias

2004-09-15

150

zebra 2  

...the removal of a boat from the water. Guidelines for boat hull cleaning, painting and antifouling are available from Miss Anne Blacker, Water Quality Unit, Environment and Heritage Service Calvert...

151

ZEBRA (Zero Energy Breeder Accelerator) program at CRNL: 300 mA to 10 MeV proton linac  

International Nuclear Information System (INIS)

ZEBRA is being designed as a test accelerator at CRNL to demonstrate operation of an injector for an electronuclear breeder that could produce fissile fuel for nuclear power reactors. Problems and characteristics of launching a high-current beam will be investigated by the 100% duty cycle 300 mA to 10 MeV proton linac. The program of work including design and testing of 100% duty cycle intermediate steps prior to ZEBRA construction are described. These steps include a 270 MHz RFQ for field breakdown measurements, a 100 mA to 1 MeV RFQ at 270 MHz high power resonant load and various low power experiments. Extension of the program in the long term is described to give a basis for the injector program

152

The zebra mussel (Dreissena polymorpha), a new pest in North America: reproductive mechanisms as possible targets of control strategies  

Science.gov (United States)

The zebra mussel (Dreissena polymorpha) has spread rapidly in temperate fresh waters of North America since its introduction into the Great Lakes in 1985 or 1986. It attaches to hard substrates, forming layers, occluding water intakes, encrusting and killing native mussels, filtering algae in competition with other planktivores, and possibly interfering with fish spawning. It reproduces prolifically, suggesting that an approach to its control may be by controlling its reproduction. Previous literature suggests that spawning in bivalves is regulated by both environmental and internal chemical cues. A suggested sequence is that phytoplankton chemicals initially trigger spawning; chemicals associated with gametes provide a species-specific pheromonal positive feedback for spawning; and the response to environmental chemicals is mediated internally by serotonin (5-HT). The role of 5-HT in zebra mussels is under investigation. Both males and females can be induced to spawn by either injection or external application of 5-HT. The response can also be activated by 8-hydroxy-2-(di-n-propylamino)-tetralin, an agonist at 5-HT1A receptors. HPLC analysis has detected 5-HT as the major biogenic amine in both male and female gonads. 5-HT immunocytochemistry demonstrates nerves containing serotonergic fibers innervating gonads of both males and females, with prominent varicosities surrounding the follicles in both sexes. A role of 5-HT in mediating spawning responses in zebra mussels is thus strongly supported. These studies have shown that reproductive behavior of zebra mussels can be modified by outside chemicals, a property that may be exploited for purposes of control.

Ram, Jeffrey L.; Fong, Peter; Croll, Roger P.; Nichols Susan J.; Wall, Darcie

1992-01-01

153

Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes.  

Science.gov (United States)

The characteristic striped appearance of zebras has provoked much speculation about its function and why the pattern has evolved, but experimental evidence is scarce. Here, we demonstrate that a zebra-striped horse model attracts far fewer horseflies (tabanids) than either homogeneous black, brown, grey or white equivalents. Such biting flies are prevalent across Africa and have considerable fitness impact on potential mammalian hosts. Besides brightness, one of the likely mechanisms underlying this protection is the polarization of reflected light from the host animal. We show that the attractiveness of striped patterns to tabanids is also reduced if only polarization modulations (parallel stripes with alternating orthogonal directions of polarization) occur in horizontal or vertical homogeneous grey surfaces. Tabanids have been shown to respond strongly to linearly polarized light, and we demonstrate here that the light and dark stripes of a zebra's coat reflect very different polarizations of light in a way that disrupts the attractiveness to tabanids. We show that the attractiveness to tabanids decreases with decreasing stripe width, and that stripes below a certain size are effective in not attracting tabanids. Further, we demonstrate that the stripe widths of zebra coats fall in a range where the striped pattern is most disruptive to tabanids. The striped coat patterns of several other large mammals may also function in reducing exposure to tabanids by similar mechanisms of differential brightness and polarization of reflected light. This work provides an experimentally supported explanation for the underlying mechanism leading to the selective advantage of a black-and-white striped coat pattern. PMID:22323196

Egri, Adám; Blahó, Miklós; Kriska, György; Farkas, Róbert; Gyurkovszky, Mónika; Akesson, Susanne; Horváth, Gábor

2012-03-01

154

Sex bias and dosage compensation in the zebra finch versus chicken genomes: General and specialized patterns among birds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We compared global patterns of gene expression between two bird species, the chicken and zebra finch, with regard to sex bias of autosomal versus Z chromosome genes, dosage compensation, and evolution of sex bias. Both species appear to lack a Z chromosome–wide mechanism of dosage compensation, because both have a similar pattern of significantly higher expression of Z genes in males relative to females. Unlike the chicken Z chromosome, which has female-specific expression of the noncoding ...

Itoh, Yuichiro; Replogle, Kirstin; Kim, Yong-hwan; Wade, Juli; Clayton, David F.; Arnold, Arthur P.

2010-01-01

155

Comparing a microbial biocide and chlorine as zebra mussel control strategies in an Irish drinking water treatment plant  

Directory of Open Access Journals (Sweden)

Full Text Available A need exists for an environmentally friendly mussel control method to replace chlorine and other traditional control methods currentlyutilised in drinking water plants and other infested facilities. Zequanox® is a newly commercialised microbial biocide for zebra and quaggamussels comprised of killed Pseudomonas fluorescens CL145A cells. The objective of this study was to compare the efficacy of adevelopmental formulation of Zequanox (referred to as MBI 401 FDP and chlorine treatments on adult and juvenile zebra mussels byrunning a biobox trial in conjunction with chlorine treatments at an infested Irish drinking water treatment plant. Since 2009, the plantmanagement has used a residual chlorine concentration of 2 mg/L in autumn to control both adult zebra mussels and juvenile settlement intheir three concrete raw water chambers. Juvenile mussel settlement was monitored in three bioboxes as well as in three treatment chambersin the plant for three months prior to treatment. Adult mussels were seeded into the chambers and bioboxes four days before treatment. InOctober 2011, the bioboxes were treated with MBI 401 FDP at 200 mg active substance/L, while chlorine treatment took place in the waterchambers. The MBI 401 FDP treatment lasted only 8 hours while chlorine treatment lasted seven days. Juvenile numbers were reduced tozero in both the bioboxes and treated chambers within seven days. Adult mussel mortality reached 80% for both the chlorine and MBI 401FDP treatment; however, mortality was achieved faster in the chlorine treatment. These results provided important insights into zebra musselcontrol alternatives to chlorine and supported further development of the now commercial product, Zequanox.

Sara Meehan

2013-06-01

156

Cannabinoid exposure during zebra finch sensorimotor vocal learning persistently alters expression of endocannabinoid signaling elements and acute agonist responsiveness  

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Full Text Available Abstract Background Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood. Such persistently altered behavior must be attributable to changes in physiological substrates responsible for song. We are currently working to identify the nature of such physiological changes, and to understand how they contribute to altered vocal learning. One possibility is that developmental agonist exposure results in altered expression of elements of endocannabinoid signaling systems. To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain. Results We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system. Conclusions Our findings indicate that the zebra finch endocannabinoid system is particularly sensitive to exogenous agonist exposure during the critical period of song learning and provide insight into susceptible brain areas.

Lichtman Aron H

2011-01-01

157

Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates  

International Nuclear Information System (INIS)

The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. - Highlights: ? The use of tissue concentrations to assess environmental metal pollution was studied. ? Metal accumulation was measured in caged zebra mussels and resident Chironomidae. ? Shell condition of mussels and macroinvertebrate taxa distribution was assessed. ? Different accumulation between biota and relations with community level were found. ? Bioaccumulation is an integrated measure of metal toxicity in aquatic communities. - Metal accumulation in selected aquatic invertebrates can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity.

158

Screening of POP pollution by AChE and EROD activities in Zebra mussels from the Italian Great Lakes.  

Science.gov (United States)

The increase of ethoxyresorufin dealkylation (EROD) and the inhibition of acetylcholinesterase (AChE) as biomarkers have been commonly used in vertebrates for the persistent organic pollutants (POPs) biomonitoring of aquatic environments, but very few studies have been performed for invertebrates. Previous researches demonstrated the interference due to some chemicals on EROD and AChE activities of the freshwater bivalve Zebra mussel (Dreissena polymorpha) in laboratory and field studies, showing its possible use for the screening of POP effects. We investigated the contamination of the Italian sub-alpine great lakes (Maggiore, Lugano, Como, Iseo, Garda) by the biomarker approach on Zebra mussel specimens collected at 17 sampling sites with different morphometric characteristics and anthropization levels. Results showed a homogeneous contamination of AChE inhibitors in Lake Garda, Maggiore, Como and Iseo with values ranging from 0.5 to 3 nmol/min/mg proteins and with an average inhibition of about 66% to controls. The planar compounds pollution, able to activate the EROD activity, seems higher in some sampling stations of Lake Garda, Como and Iseo (2-4 pmol/min/mg proteins) than that measured in Lake Lugano (1.5-3 pmol/min/mg proteins). On the contrary, the enzyme activity in Lake Maggiore showed an interesting opposite effect of AhR-binding compounds and trace metals. Finally, the possible use of Zebra mussel specimens maintained at laboratory conditions as controls against the selection of the less polluted sampling site is discussed. PMID:16263378

Binelli, A; Ricciardi, Francesco; Riva, Consuelo; Provini, Alfredo

2005-12-01

159

Hydrologic controls and anthropogenic drivers of the zebra mussel invasion of the Mississippi-Missouri river system  

Science.gov (United States)

We propose a novel ecohydrological model for the invasion of inland waters by the zebra mussel Dreissena polymorpha and test it against field data gathered within the Mississippi-Missouri river system in North America. This biological invasion poses major ecological and economic threats, especially due to the huge population densities reached by local zebra mussel colonies and the species' unparalleled dispersal abilities within fluvial systems. We focus on a quantitative evaluation, attempted here for the first time, of the individual roles and the mutual interactions of drivers and controls of the Mississippi-Missouri invasion. To this end, we use a multilayer network model accounting explicitly for zebra mussel demographic dynamics, hydrologic transport, and dispersal due to anthropic activities. By testing our results against observations, we show that hydrologic transport alone is not sufficient to explain the spread of the species at the basin scale. We also quantify the role played by commercial navigation in promoting the initial, selective colonization of the river system, and show how recreational boating may have determined the capillary penetration of the species into the water system. The role of post-establishment dispersal mechanisms and the effectiveness of possible prevention measures are also discussed in the context of model sensitivity and robustness to reparametrization.

Mari, L.; Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Levin, S. A.; Rodriguez-Iturbe, I.; Rinaldo, A.

2011-03-01

160

Increased benthic algal primary production in response to the invasive zebra mussel (Dreissena polymorpha) in a productive ecosystem, Oneida Lake, New York.  

Science.gov (United States)

Increased water clarity associated with zebra mussel (Dreissena polymorpha) populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplankton production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates benthic primary production in Oneida Lake, NY before and after zebra mussel invasion (1992), using measured photosynthetic parameters (, alpha(B) and beta) from sampled benthic algal communities. In the summers of 2003 and 2004, primary production was measured as O(2) evolution from algal communities on hard (cobble) and soft (sediment) substrate from several depths. We also backcast estimates of benthic primary production from measurements of light penetration since 1975. Estimates of whole-lake epipelic and epilithic algal primary production showed a significant (4%) increase and exhibited significantly less interannual variability subsequent to the establishment of zebra mussels. We applied our model to two lakes of differing trophic status; the model significantly overestimated benthic primary production in a hypereutrophic lake, but there was no significant difference between the actual and predicted primary production values in the oligotrophic lake. The hypereutrophic lake had higher zebra mussel densities than Oneida (224 vs. 41 per sample respectively). Though total community respiration (measured in total darkness) was factored into our model predictions of production, our model may need modification when heterotrophic respiration is a large portion of total community metabolism. PMID:19017132

Cecala, Rebecca K; Mayer, Christine M; Schulz, Kimberly L; Mills, Edward L

2008-11-01

 
 
 
 
161

Increased activity correlates with reduced ability to mount immune defenses to endotoxin in zebra finches.  

Science.gov (United States)

When suffering from infection, animals experience behavioral and physiological alterations that potentiate the immune system's ability to fight pathogens. The behavioral component of this response, termed "sickness behavior," is characterized by an overall reduction in physical activity. A growing number of reports demonstrate substantial flexibility in these sickness behaviors, which can be partially overcome in response to mates, intruders and parental duties. Since it is hypothesized that adopting sickness behaviors frees energetic resources for mounting an immune response, we tested whether diminished immune responses coincided with reduced sickness behaviors by housing male zebra finches (Taeniopygia guttata) in social conditions that alter their behavioral response to an endotoxin. To facilitate our data collection, we developed and built a miniaturized sensor capable of detecting changes in dorsoventral acceleration and categorizing them as different behaviors when attached to the finches. We found that the immune defenses (quantified as haptoglobin-like activity, ability to change body temperature and bacterial killing capacity) increased as a function of increased time spent resting. The findings indicate that when animals are sick attenuation of sickness behaviors may exact costs, such as reduced immune function. The extent of these costs depends on how relevant the affected components of immunity are for fighting a specific infection. J. Exp. Zool. 321A: 422-431, 2014. © 2014 Wiley Periodicals, Inc. PMID:24888267

Lopes, Patricia C; Springthorpe, Dwight; Bentley, George E

2014-10-01

162

Cave crawling in zebra Finch skulls: Which anatomical structures constitute the functional intraaural Canal?  

DEFF Research Database (Denmark)

The middle ears of birds are acoustically coupled through an air-filled interaural canal, often illustrated and modelled as a simple tube. It allows sound to propagate through the skull from one ear to the other and considerably enhance the cues for directional hearing by interaction with the external sound field driving the eardrum vibrations. Theoretically, different combinations of frequency dependent gains and delays of sound in the interaural canal can produce very different directionalities of the ears but it still remains uncertain how interaural transmission gain and delay can be shaped by anatomical adaptations during evolution. A closer inspection of the zebra finch cranium using micro-CT scanning reveals that not only is IAC trabeculated and irregularly shaped but it also communicates with a set of highly complex, air-filled canals in the skull extending to the base of the beak. We tested the possible influence of these communicating cavities by measuring eardrum directionality and interaural transmission before and after filling the frontal cavities with dyed fat but found no dramatic effects. We will discuss what function the cavities serve and whether the ICA should be represented by a simple tube in future models

Larsen, Ole Næsbye; Salomon, Rasmus

163

Maternal Antibody Transfer Can Lead to Suppression of Humoral Immunity in Developing Zebra Finches (Taeniopygia guttata).  

Science.gov (United States)

Abstract Maternally transferred antibodies have been documented in a wide range of taxa and are thought to adaptively provide protection against parasites and pathogens while the offspring immune system is developing. In most birds, transfer occurs when females deposit immunoglobulin Y into the egg yolk, and it is proportional to the amount in the female's plasma. Maternal antibodies can provide short-term passive protection as well as specific and nonspecific immunological priming, but high levels of maternal antibody can result in suppression of the offspring's humoral immune response. We injected adult female zebra finches (Taeniopygia guttata) with one of two antigens (lipopolysaccharide [LPS] or keyhole limpet hemocyanin [KLH]) or a control and then injected offspring with LPS, KLH, or a control on days 5 and 28 posthatch to examine the impact of maternally transferred antibodies on the ontogeny of the offspring's humoral immune system. We found that offspring of females exposed to KLH had elevated levels of KLH-reactive antibody over the first 17-28 days posthatch but reduced KLH-specific antibody production between days 28 and 36. We also found that offspring exposed to either LPS or KLH exhibited reduced total antibody levels, compared to offspring that received a control injection. These results indicate that high levels of maternal antibodies or antigen exposure during development can have negative repercussions on short-term antibody production and may have long-term fitness repercussions for the offspring. PMID:25244385

Merrill, Loren; Grindstaff, Jennifer L

2014-01-01

164

Lifelong exposure to methylmercury disrupts stress-induced corticosterone response in zebra finches (Taeniopygia guttata).  

Science.gov (United States)

Mercury can disrupt the endocrine systems of mammals and fish, but little is known about its effects on avian hormones. The authors employed an experimental manipulation to show that methylmercury suppresses the stress-induced corticosterone response in birds, an effect previously unreported in the literature. Corticosterone regulates many normal metabolic processes, such as the maintenance of proper blood glucose levels during stressful daily fasting; an inability to increase corticosterone levels in response to stressors renders a bird less able to face a wide array of environmental challenges. The authors studied reproductively mature zebra finches that had been exposed to 0.0?µg/g, 0.3?µg/g, 0.6?µg/g, 1.2?µg/g, or 2.4?µg/g (wet wt) dietary methylmercury throughout their life (i.e., from the egg onward). In contrast to some field studies, the present study found no significant change in baseline plasma corticosterone concentrations attributable to chronic methylmercury exposure. However, a comparison between the baseline corticosterone levels and levels after 30?min of handling stress revealed that the ability of birds to mount a stress response was reduced with increasing blood total mercury concentration. These results are consistent with adrenal corticoid disruption caused by chronic mercury exposure and mirror a similar study on free-living nestling songbirds exposed to environmental mercury. PMID:24436046

Moore, Christina S; Cristol, Daniel A; Maddux, Sarah L; Varian-Ramos, Claire W; Bradley, Eric L

2014-05-01

165

Ontogeny and individual variation in the adrenocortical response of zebra finch (Taeniopygia guttata) nestlings.  

Science.gov (United States)

Numerous studies indicate interspecies variation in the ontogeny of the adrenocortical response in birds; however, little is known about the extent of interindividual variation in avian young. Toward this end, we examined the ontogeny and interindividual variation in the adrenocortical response in zebra finch (Taeniopygia guttata) nestlings. We measured baseline and stress-induced total (bound and free) corticosterone, corticosteroid binding globulin capacity, and resulting estimated free corticosterone levels in nestlings of four different ages (days 5, 10, 16, and 21). In addition, we investigated the potential correlates of interindividual variation (brood size and mass). Nestlings at days 5 and 10 post-hatching showed no significant increase in total or free corticosterone levels in response to a standardized handling stress, whereas an adult-like stress response was seen by day 16 post-hatching. There was large interindividual (fivefold) variation in both baseline and stress-induced corticosterone among individual nestlings at any age. We estimate that half of this individual variation in the adrenocortical response could be explained by between-clutch variation (e.g., genetics), while the other half could be explained by other factors such as rearing environment (based on estimated intraclass correlation coefficients). Total baseline corticosterone, but not stress-induced corticosterone, was negatively correlated with fledging mass in this species. PMID:19426109

Wada, Haruka; Salvante, Katrina G; Wagner, Emily; Williams, Tony D; Breuner, Creagh W

2009-01-01

166

Cave crawling in zebra Finch skulls : Which anatomical structures constitute the functional intraaural Canal?  

DEFF Research Database (Denmark)

The middle ears of birds are acoustically coupled through an air-filled interaural canal, often illustrated and modelled as a simple tube. It allows sound to propagate through the skull from one ear to the other and considerably enhance the cues for directional hearing by interaction with the external sound field driving the eardrum vibrations. Theoretically, different combinations of frequency dependent gains and delays of sound in the interaural canal can produce very different directionalities of the ears but it still remains uncertain how interaural transmission gain and delay can be shaped by anatomical adaptations during evolution. A closer inspection of the zebra finch cranium using micro-CT scanning reveals that not only is IAC trabeculated and irregularly shaped but it also communicates with a set of highly complex, air-filled canals in the skull extending to the base of the beak. We tested the possible influence of these communicating cavities by measuring eardrum directionality and interaural transmission before and after filling the frontal cavities with dyed fat but found no dramatic effects. We will discuss what function the cavities serve and whether the ICA should be represented by a simple tube in future models

Larsen, Ole Næsbye; Salomon, Rasmus

167

EFFECTS OF ORGANOPHOSPHATES ON ACUTE POISONING AND ACETYL CHOLINESTERASE INHIBITION IN ZEBRA FISH  

Directory of Open Access Journals (Sweden)

Full Text Available Organophosphates (Ops. are the most widely used insecticides available today. These are a group of insecticides used in chemical sprays to kill bugs, and insects in orchards, vineyards, vegetables and cereal crops. The present study examined effects of the pesticide Methyl parathion, Dichlorvos and Chlorpyrifos on adult zebra fish were exposed to various concentrations (5, 10 & 25mg/L for 24 and 48hrs acute toxic study. Chlorpyrifos showed mortality in all concentrations and Methyl parathion and Dichlorvos showed the same in 25 mg/L. LC 50 value for Methyl parathion and Dichlorvos was 5 & 10 mg/L respectively. The total protein, LPO content was increased except SOD, Catalase in the brain tissue of the treated fishes.  There was no significant decrease in the GPX activity at 5ppm test groups. The GPX activity decreased significantly in test group treated with 10ppm and a significant difference was found between 5ppm and 10ppm test groups. The histopathological studies of brain tissue showed that neuronal degeneration and tissue damages in the brain of treated fishes when compared with the control. Ops. produce toxicity by inhibiting the cholinesterase enzymes in the nervous system. Monitoring of acetyl cholinesterase (AChE inhibition has been widely used in terrestrial and freshwater aquatic systems as an indicator of OP exposure and effects.

TH Sukirtha* MV Usharani

2013-03-01

168

Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes  

Energy Technology Data Exchange (ETDEWEB)

Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. - Significant levels of DDTs and PCBs are still present in the Italian subalpine great lakes.

Riva, Consuelo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)], E-mail: consuelo.riva@unimi.it; Binelli, Andrea; Provini, Alfredo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)

2008-02-15

169

Social experience affects neuronal responses to male calls in adult female zebra finches.  

Science.gov (United States)

Plasticity studies have consistently shown that behavioural relevance can change the neural representation of sounds in the auditory system, but what occurs in the context of natural acoustic communication where significance could be acquired through social interaction remains to be explored. The zebra finch, a highly social songbird species that forms lifelong pair bonds and uses a vocalization, the distance call, to identify its mate, offers an opportunity to address this issue. Here, we recorded spiking activity in females while presenting distance calls that differed in their degree of familiarity: calls produced by the mate, by a familiar male, or by an unfamiliar male. We focused on the caudomedial nidopallium (NCM), a secondary auditory forebrain region. Both the mate's call and the familiar call evoked responses that differed in magnitude from responses to the unfamiliar call. This distinction between responses was seen both in single unit recordings from anesthetized females and in multiunit recordings from awake freely moving females. In contrast, control females that had not heard them previously displayed responses of similar magnitudes to all three calls. In addition, more cells showed highly selective responses in mated than in control females, suggesting that experience-dependent plasticity in call-evoked responses resulted in enhanced discrimination of auditory stimuli. Our results as a whole demonstrate major changes in the representation of natural vocalizations in the NCM within the context of individual recognition. The functional properties of NCM neurons may thus change continuously to adapt to the social environment. PMID:22512260

Menardy, F; Touiki, K; Dutrieux, G; Bozon, B; Vignal, C; Mathevon, N; Del Negro, C

2012-04-01

170

Mitochondrial haplotype does not affect sperm velocity in the zebra finch Taeniopygia guttata.  

Science.gov (United States)

Mitochondrial DNA (mtDNA) variation has been suggested as a possible cause of variation in male fertility because sperm activity is tightly coupled to mitochondrial oxidative phosphorylation and ATP production, both of which are sensitive to mtDNA mutations. Since male-specific phenotypes such as sperm have no fitness consequences for mitochondria due to maternal mitochondrial (and mtDNA) inheritance, mtDNA mutations that are deleterious in males but which have negligible or no fitness effect in females can persist in populations. How often such mutations arise and persist is virtually unknown. To test whether there were associations between mtDNA variation and sperm performance, we haplotyped 250 zebra finches Taeniopygia guttata from a large pedigreed-population and measured sperm velocity using computer-assisted sperm analysis. Using quantitative genetic 'animal' models, we found no effect of mtDNA haplotype on sperm velocity. Therefore, there is no evidence that in this system mitochondrial mutations have asymmetric fitness effects on males and females, leading to genetic variation in male fertility that is blind to natural selection. PMID:20040001

Mossman, J A; Slate, J; Birkhead, T R

2010-02-01

171

A Very Small and Super Strong Zebra Pattern Burst at the Beginning of a Solar Flare  

Science.gov (United States)

Microwave emission with spectral zebra pattern structures (ZPs) is frequently observed in solar flares and the Crab pulsar. The previous observations show that ZP is a structure only overlapped on the underlying broadband continuum with slight increments and decrements. This work reports an unusually strong ZP burst occurring at the beginning of a solar flare observed simultaneously by two radio telescopes located in China and the Czech Republic and by the EUV telescope on board NASA's satellite Solar Dynamics Observatory on 2013 April 11. It is a very short and super strong explosion whose intensity exceeds several times that of the underlying flaring broadband continuum emission, lasting for just 18 s. EUV images show that the flare starts from several small flare bursting points (FBPs). There is a sudden EUV flash with extra enhancement in one of these FBPs during the ZP burst. Analysis indicates that the ZP burst accompanying an EUV flash is an unusual explosion revealing a strong coherent process with rapid particle acceleration, violent energy release, and fast plasma heating simultaneously in a small region with a short duration just at the beginning of the flare.

Tan, Baolin; Tan, Chengming; Zhang, Yin; Huang, Jing; Mészárosová, Hana; Karlický, Marian; Yan, Yihua

2014-08-01

172

Inner-shell radiation from wire array implosions on the Zebra generator  

Energy Technology Data Exchange (ETDEWEB)

Implosions of brass wire arrays on Zebra have produced L-shell radiation as well as inner-shell K? and K? transitions. The L-shell radiation comes from ionization stages around the Ne-like charge state that is largely populated by a thermal electron energy distribution function, while the K-shell photons are a result of high-energy electrons ionizing or exciting an inner-shell (1s) electron from ionization stages around Ne-like. The K- and L-shell radiations were captured using two time-gated and two axially resolved time-integrated spectrometers. The electron beam was measured using a Faraday cup. A multi-zone non-local thermodynamic equilibrium pinch model with radiation transport is used to model the x-ray emission from experiments for the purpose of obtaining plasma conditions. These plasma conditions are used to discuss some properties of the electron beam generated by runaway electrons. A simple model for runaway electrons is examined to produce the K? radiation, but it is found to be insufficient.

Ouart, N. D.; Giuliani, J. L.; Dasgupta, A. [Plasma Physics Division, Naval Research Laboratory, Washington, District of Columbia 20375 (United States); Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Shrestha, I.; Weller, M. E.; Shlyaptseva, V.; Osborne, G. C.; Stafford, A.; Keim, S. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); Apruzese, J. P. [Consultant to NRL through Engility Corp., Chantilly, Virginia 20151 (United States); Clark, R. W. [Berkeley Research Associates, Beltsville, Maryland 20705 (United States)

2014-03-15

173

ZebraBeat: a flexible platform for the analysis of the cardiac rate in zebrafish embryos  

Science.gov (United States)

Heartbeat measurement is important in assesssing cardiac function because variations in heart rhythm can be the cause as well as an effect of hidden pathological heart conditions. Zebrafish (Danio rerio) has emerged as one of the most useful model organisms for cardiac research. Indeed, the zebrafish heart is easily accessible for optical analyses without conducting invasive procedures and shows anatomical similarity to the human heart. In this study, we present a non-invasive, simple, cost-effective process to quantify the heartbeat in embryonic zebrafish. To achieve reproducibility, high throughput and flexibility (i.e., adaptability to any existing confocal microscope system and with a user-friendly interface that can be easily used by researchers), we implemented this method within a software program. We show here that this platform, called ZebraBeat, can successfully detect heart rate variations in embryonic zebrafish at various developmental stages, and it can record cardiac rate fluctuations induced by factors such as temperature and genetic- and chemical-induced alterations. Applications of this methodology may include the screening of chemical libraries affecting heart rhythm and the identification of heart rhythm variations in mutants from large-scale forward genetic screens.

de Luca, Elisa; Zaccaria, Gian Maria; Hadhoud, Marwa; Rizzo, Giovanna; Ponzini, Raffaele; Morbiducci, Umberto; Santoro, Massimo Mattia

2014-05-01

174

Making the best of a pest: the potential for using invasive zebra mussel (dreissena polymorpha) biomass as a supplement to commercial chicken feed.  

Science.gov (United States)

Invasive non-native species frequently occur in very high densities. When such invaders present an economic or ecological nuisance, this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability of dried, whole zebra mussels as a supplement to poultry feed, thus providing a more attractive end-use than disposal to landfill. Measurable outcomes were nutrient and energy composition analyses of the feeds and production parameters of the birds over a 14 day period. Zebra mussels were a palatable feed supplement for chickens. The mussel meal contained high levels of calcium (344.9 g kg(-1)), essential for egg shell formation, which was absorbed and retained easily by the birds. Compared with standard feed, a mussel-supplemented diet caused no significant effects on production parameters such as egg weight and feed conversion ratio during the study period. However, protein and energy levels in the zebra mussel feed were much lower than expected from the literature. In order for zebra mussels to be a viable long-term feed supplement for poultry, flesh would need to be separated from the shells in an economically viable way. If zebra mussels were to be used with the shells remaining, it seems that the resultant mussel meal would be more suitable as a calcium supplement. PMID:25106778

McLaughlan, Claire; Rose, Paul; Aldridge, David C

2014-11-01

175

Making the Best of a Pest: The Potential for Using Invasive Zebra Mussel ( Dreissena Polymorpha) Biomass as a Supplement to Commercial Chicken Feed  

Science.gov (United States)

Invasive non-native species frequently occur in very high densities. When such invaders present an economic or ecological nuisance, this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability of dried, whole zebra mussels as a supplement to poultry feed, thus providing a more attractive end-use than disposal to landfill. Measurable outcomes were nutrient and energy composition analyses of the feeds and production parameters of the birds over a 14 day period. Zebra mussels were a palatable feed supplement for chickens. The mussel meal contained high levels of calcium (344.9 g kg-1), essential for egg shell formation, which was absorbed and retained easily by the birds. Compared with standard feed, a mussel-supplemented diet caused no significant effects on production parameters such as egg weight and feed conversion ratio during the study period. However, protein and energy levels in the zebra mussel feed were much lower than expected from the literature. In order for zebra mussels to be a viable long-term feed supplement for poultry, flesh would need to be separated from the shells in an economically viable way. If zebra mussels were to be used with the shells remaining, it seems that the resultant mussel meal would be more suitable as a calcium supplement.

McLaughlan, Claire; Rose, Paul; Aldridge, David C.

2014-11-01

176

Mitochondrial uncoupling as a regulator of life-history trajectories in birds: an experimental study in the zebra finch.  

Science.gov (United States)

Mitochondria have a fundamental role in the transduction of energy from food into ATP. The coupling between food oxidation and ATP production is never perfect, but may nevertheless be of evolutionary significance. The 'uncoupling to survive' hypothesis suggests that 'mild' mitochondrial uncoupling evolved as a protective mechanism against the excessive production of damaging reactive oxygen species (ROS). Because resource allocation and ROS production are thought to shape animal life histories, alternative life-history trajectories might be driven by individual variation in the degree of mitochondrial uncoupling. We tested this hypothesis in a small bird species, the zebra finch (Taeniopygia guttata), by treating adults with the artificial mitochondrial uncoupler 2,4-dinitrophenol (DNP) over a 32-month period. In agreement with our expectations, the uncoupling treatment increased metabolic rate. However, we found no evidence that treated birds enjoyed lower oxidative stress levels or greater survival rates, in contrast to previous results in other taxa. In vitro experiments revealed lower sensitivity of ROS production to DNP in mitochondria isolated from skeletal muscles of zebra finch than mouse. In addition, we found significant reductions in the number of eggs laid and in the inflammatory immune response in treated birds. Altogether, our data suggest that the 'uncoupling to survive' hypothesis may not be applicable for zebra finches, presumably because of lower effects of mitochondrial uncoupling on mitochondrial ROS production in birds than in mammals. Nevertheless, mitochondrial uncoupling appeared to be a potential life-history regulator of traits such as fecundity and immunity at adulthood, even with food supplied ad libitum. PMID:25063856

Stier, Antoine; Bize, Pierre; Roussel, Damien; Schull, Quentin; Massemin, Sylvie; Criscuolo, François

2014-10-01

177

The acoustic expression of stress in a songbird: does corticosterone drive isolation-induced modifications of zebra finch calls?  

Science.gov (United States)

Animal vocalizations convey multiple pieces of information about the sender. Some of them are stable, such as identity or sex, but others are labile like the emotional or motivational state. Only a few studies have examined the acoustic expression of emotional state in non-human animals and related vocal cues to physiological parameters. In this paper, we examined the vocal expression of isolation-induced stress in a songbird, the zebra finch (Taeniopygia guttata). Although songbirds use acoustic communication extensively, nothing is known to date on how they might encode physiological states in their vocalizations. We tested the hypothesis that social isolation in zebra finches induces a rise of plasma corticosterone that modifies the vocal behavior. We monitored plasma corticosterone, as well as call rate and acoustic structure of calls of males in response to the playback of female calls of varied saliences (familiar versus stranger) in two situations: social isolation and social housing. Social isolation induced both a rise in plasma corticosterone, and a range of modifications in males' vocal behavior. Isolated birds showed a lower vocal activity, an abolition of the difference of response between the two stimuli, and evoked calls with longer duration and higher pitch. Because some of these effects were mimicked after oral administration of corticosterone in socially housed subjects, we conclude that corticosterone could be partly responsible for the isolation-related modifications of calls in male zebra finches. To our knowledge, this is the first demonstration of the direct implication of glucocorticoids in the modulation of the structure of vocal sounds. PMID:22387308

Perez, Emilie C; Elie, Julie E; Soulage, Christophe O; Soula, Hédi A; Mathevon, Nicolas; Vignal, Clémentine

2012-04-01

178

Population dynamics of zebra mussels Dreissena polymorpha (Pallas, 1771) during the initial invasion of the Upper Mississippi River, USA  

Science.gov (United States)

The aim of this study was to document and model the population dynamics of zebra mussels Dreissena polymorpha (Pallas, 1771) in Pool 8 of the Upper Mississippi River (UMR), USA, for five consecutive years (1992-1996) following their initial discovery in September 1991. Artificial substrates (concrete blocks, 0.49 m2 surface area) were deployed on or around the first of May at two sites within each of two habitat types (main channel border and contiguous backwater). Blocks were removed monthly (30 ?? 10 d) from the end of May to the end of October to obtain density and growth information. Some blocks deployed in May 1995 were retrieved in April 1996 to obtain information about overwinter growth and survival. The annual density of zebra mussels in Pool 8 of the UMR increased from 3.5/m2 in 1992 to 14,956/m 2 in 1996. The average May-October growth rate of newly recruited individuals, based on a von Bertalanffy growth model fitted to monthly shell-length composition data, was 0.11 mm/d. Model estimates of the average survival rate varied from 21 to 100% per month. Estimated recruitment varied substantially among months, with highest levels occurring in September-October of 1994 and 1996, and in July of 1995. Recruitment and density in both habitat types increased by two orders of magnitude in 1996. Follow-up studies will be necessary to assess the long-term stability of zebra mussel populations in the UMR; this study provides the critical baseline information needed for those future comparisons. ?? Published by Oxford University Press on behalf of The Malacological Society of London 2006.

Cope, W.G.; Bartsch, M.R.; Hightower, J.E.

2006-01-01

179

Impact of the zebra mussel Dreissena polymorpha invasion on the budget of suspended material in a shallow lagoon ecosystem  

Science.gov (United States)

The role of the zebra mussel Dreissena polymorpha in redistribution of total particulate material (TPM) between the water column and bottom sediment was estimated using the TPM budget for a mussel bed in the Curonian lagoon, the Baltic Sea. Seasonal clearance rates were derived from the TPM budget assuming two resuspension scenarios: no resuspension and full resuspension of biodeposits. Estimated clearance rates for both scenarios were compared with the rates calculated from the population clearance rate model. Seasonal clearance rates estimated using the population model (1.1 and 11.8 l g-1 SFDW day-1) fitted well into the interval of seasonal clearance rates calculated from TPM budgets assuming no resuspension of biodeposits (3.2 and 21.4 l g SFDW-1 day-1). In the scenario with biodeposits resuspension clearance rates were much higher (57.4 and 148.9 g SFDW-1 day-1). The ratio of clearance to residence time was highly dependent on the fate of biodeposits. Therefore its use in interpretation of the species impact on TPM was limited. An alternative measure based on the ratio of the amount of TPM biodeposited to TPM transported into the bed was used. It was found that zebra mussels are able to deposit between 10 and 30% of the incoming TPM, and the amount of biodeposited material was correlated with water residence time. Results indicate that the impact of zebra mussels on TPM in the lagoon is small relative to the high transport rates of TPM over the bed. However, annual biosedimentation rate (~590 g m-2) in the mussel bed was higher than physical deposition rate (~380 g m-2) in accumulation areas devoid of large suspension feeders. We suggest that a local impact due to enhanced availability of organic material to other trophic groups of associated benthic organisms may be more significant than effects on TPM pathways at an ecosystem scale.

Daunys, Darius; Zemlys, Petras; Olenin, Sergej; Zaiko, Anastasija; Ferrarin, Christian

2006-05-01

180

Water Quality Impacts and Indicators of the Metabolic Activity of the Zebra Mussel Invasion of the Seneca River  

Science.gov (United States)

The conspicuous shifts in summertime values of common measures of water qualify that have persisted for 10 years (1993 to 2002) in the Seneca River, New York, as a result of the zebra mussel invasion are documented. Resolution of patterns in time and space is supported by water quality monitoring that extends back to the late 1970s. Patterns are evaluated to describe the stability of impacts and quantify metabolic activity of the invader. The water quality impacts that have persisted unabated for 10 years since the invasion are the most severe documented for a river in North America. Changes in summer median conditions since the invasion include: (1) a 16-fold decrease in chlorophyll concentration (Chl), (2) a 2.5-fold increase in Secchi disc transparency, (3) a 17-fold increase in soluble reactive phosphorus concentration, (4) a 3.7-fold increase in total ammonia concentration, (5) a greater than 25 percent decrease in dissolved oxygen (DO) concentration, and (6) a decrease in pH of 0.55 units. The strength of these signatures has been driven by anthropogenic influences that include upstream nutrient loading and morphometric modifications of the river, and the functioning of Cross Lake, through which the river flows. This hypereutrophic lake sustains dense zebra mussel populations and related water quality impacts in the river downstream of the lake outflow by acting as a source of veligers and suitable food for this bivalve. Evidence is presented that levels of metabolic activity of the zebra mussel in this river have been resource limited, manifested through increased consumption of Chl and DO with increased delivery of these constituents in the lake's outflow.

Effler, Steven W.; Matthews, David A.; Brooks-Matthews, Carol M.; Perkins, Mary Gail; Siegfried, Clifford A.; Hassett, James M.

2004-06-01

 
 
 
 
181

In search of greener pastures: Using satellite images to predict the effects of environmental change on zebra migration  

Science.gov (United States)

ungulate migrations occurred in most grassland and boreal woodland ecosystems, but many have been lost due to increasing habitat loss and fragmentation. With the rate of environmental change increasing, identifying and prioritizing migration routes for conservation has taken on a new urgency. Understanding the cues that drive long-distance animal movements is critical to predicting the fate of migrations under different environmental change scenarios and how large migratory herbivores will respond to increasing resource heterogeneity and anthropogenic influences. We used an individual-based modeling approach to investigate the influence of environmental conditions, monitored using satellite data, on departure date and movement speed of migrating zebras in Botswana. Daily zebra movements between dry and rainy season ranges were annotated with coincident observations of precipitation from the Tropical Rainfall Measuring Mission data set and Moderate Resolution Imaging Spectroradiometer-derived normalized difference vegetation index (NDVI). An array of increasingly complex movement models representing alternative hypotheses regarding the environmental cues and controls for movement was parameterized and tested. The best and most justified model predicted daily zebra movement as two linear functions of precipitation rate and NDVI and included a modeled departure date as a function of cumulative precipitation. The model was highly successful at replicating both the timing and pace of seven actual migrations observed using GPS telemetry (R2 = 0.914). It shows how zebras rapidly adjust their movement to changing environmental conditions during migration and are able to reverse migration to avoid adverse conditions or exploit renewed resource availability, a nomadic behavior which should lend them a degree of resilience to climate and environmental change. Our results demonstrate how competing individual-based migration models, informed by freely available satellite data, can be used to evaluate the weight of evidence for multiple hypotheses regarding the use of environmental cues in animal movement. This modeling framework can be applied to quantify how animals adapt the timing and pace of their movements to prevailing environmental conditions and to forecast migrations in near real time or under alternative environmental scenarios.

Bartlam-Brooks, Hattie L. A.; Beck, Pieter S. A.; Bohrer, Gil; Harris, Stephen

2013-12-01

182

Defensin of the zebra mussel (Dreissena polymorpha): molecular structure, in vitro expression, antimicrobial activity, and potential functions.  

Science.gov (United States)

A 409 bp full length defensin gene was cloned and sequenced based on an expressed sequence tag (EST) obtained from a normalized zebra mussel (Dreissena polymorpha) foot cDNA library developed in our laboratory. The D. polymorpha defensin (Dpd) gene encoded a peptide with 76 amino acid residues. The mature Dpd contains 54 amino acids with a fully functional insect defensin A domain. Homologue searching against GenBank database suggested that this Dpd was phylogenetically close to defensins from a group of insects with six conserved cysteine residues. Predicted with homology-modeling method, the three-dimensional structure of Dpd also demonstrated a significant similarity with insect defensin A. The recombinant Dpd was in vitro expressed through an Escherichia coli expression system. The antimicrobial activities of the refolded recombinant Dpd were found against the growth of Morganella sp., Plesiomonas shigelloides, Edwardsiella tarda, E. coli and Staphylococcus aureus aureus (ATCC12598) with the minimal inhibition concentration (MIC) 0.35, 0.43, 1.16, 6.46, and 30.39 microM, respectively. However, with less than 50 microM no detectable inhibition activities were observed against the other four Gram-negative bacteria (Aeromonas salmonicida salmonicida, Motile Aeromonas, Flavobacterium sp., Pseudomonas fluorescens, Shewanella putrifaciens), as well as the other Gram-positive bacteria (Bacillus megaterium ATCC14581, Carnobacterium maltaromaticum ATCC27865, Enterococcus faecalis ATCC19433, and Micrococcus leteus ATCC4698), and the yeast Saccharomyces cerevisiae. The RNA fluorescent in situ hybridization (FISH) of Dpd in the zebra mussel suggested that the Dpd was expressed in a variety of tissues, such as foot, retractor muscle, ctenidium, mantle, hemocytes, gonad, digestive gland, and intestine. By using the quantitative PCR, the expression level of Dpd in the zebra mussel foot was the highest, followed by the muscle. By comparing the amount of Dpd transcripts in the zebra mussel foot under two different byssogenesis conditions (byssogenesis and non-byssogenesis) with qPCR, we found that the higher expression levels of Dpd were always associated with the byssogenesis status from 2 to 4 days after the start of byssogenesis. Findings of this study suggest that the expression of the Dpd gene was upregulated in vivo by byssogeneis, and by hemocytes in vitro upon stimulation with microbial antigens. PMID:20537393

Xu, Wei; Faisal, Mohamed

2010-07-01

183

PAW [Physics Analysis Workstation] at Fermilab: CORE based graphics implementation of HIGZ [High Level Interface to Graphics and Zebra  

International Nuclear Information System (INIS)

The Physics Analysis Workstation system (PAW) is primarily intended to be the last link in the analysis chain of experimental data. The graphical part of PAW is based on HIGZ (High Level Interface to Graphics and Zebra), which is based on the OSI and ANSI standard Graphics Kernel System (GKS). HIGZ is written in the context of PAW. At Fermilab, the CORE based graphics system DI-3000 by Precision Visuals Inc., is widely used in the analysis of experimental data. The graphical part of the PAW routines has been totally rewritten and implemented in the Fermilab environment. 3 refs

184

Connections of a motor cortical region in zebra finches: relation to pathways for vocal learning.  

Science.gov (United States)

The lateral magnocellular nucleus of the anterior neostriatum (lMAN) is necessary for both initial learning of vocal patterns in developing zebra finches, as well as for modification of adult song under some circumstances. Lateral MAN is composed of two subregions: a core of magnocellular neurons and a surrounding shell composed primarily of parvocellular neurons. Neurons in lMAN(core) project to a region of motor cortex known as robust nucleus of the archistriatum (RA), whereas neurons in lMAN(shell) project to a region adjacent to RA known as dorsal archistriatum (Ad). We studied the axonal connections of Ad in adult male zebra finches. In contrast to RA, Ad neurons make a large number of efferent projections, which do not include direct inputs to vocal or respiratory motor neurons. The major efferent projections of Ad are to: (1) the striatum of avian basal ganglia; (2) a dorsal thalamic zone (including the song-control nuclei dorsomedial nucleus of the posterior thalamus [DMP] and dorsolateral nucleus of the medial thalamus [DLM]); (3) restricted regions within the lateral hypothalamus (stratum cellulare externum [SCE]), which may also relay information to the same dorsal thalamic zone; (4) a nucleus in the caudal thalamus (medial spiriform nucleus [SpM]); (5) deep layers of the tectum, which project to the thalamic song-control nucleus Uva; (6) broad regions of pontine and midbrain reticular formation; and (7) areas within the ventral tegmental area and substantia nigra (ventral tegmental area [AVT], substantia nigra [SN]), which overlap with regions that project to Area X, a song-control nucleus of avian striatum. Inputs to Ad derive not only from lMAN(shell), but also from a large area of dorsolateral caudal neostriatum (dNCL), which also receives input from lMAN(shell). That is, lMAN(shell) neurons project directly to Ad, and also multisynaptically to Ad via dNCL. Double-labeling studies show that lMAN(shell) contains two different populations of projection neurons: one that projects to Ad and another to dNCL. These results are exciting for two main reasons. The first is that some of these projections represent potential closed-loop circuits that could relay information back to song-control nuclei of the telencephalon, possibly allowing diverse types of song-related information to be both integrated between loops and compared during the period of auditory-motor integration. Because both auditory experience with an adult (tutor) song pattern and auditory feedback are essential to vocal learning, closed-loop pathways could serve as comparator circuits in which efferent commands, auditory feedback, and the memory of the tutor song are compared in an iterative fashion to achieve a gradual refinement of vocal production until it matches the tutor song. In addition, these circuits seem to have a strong integrative and limbic flavor. That is, the axonal connections of Ad neurons clearly include regions that receive inputs not only from somatosensory, visual, and auditory areas of cortex, but also from limbic regions, suggesting that they may be involved in higher order sensory processing, arousal, and motivation. PMID:10753310

Bottjer, S W; Brady, J D; Cribbs, B

2000-05-01

185

Audience Effect Alters Male Mating Preferences in Zebra Finches (Taeniopygia guttata)  

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The social environment of animals strongly influences the mating preferences of both the choosing and the observing individuals. Notably, there is recent evidence that polygamous males decrease their selectivity when being observed by competitors in order to direct their rivals’ attention away from their true interest and, consequently, reduce sperm competition risk. Yet, other mechanisms, whose importance remains unexplored, could induce similar effects. In monogamous species with mutual choice, particularly, if males adjust their selectivity according to the risk of being rejected by their preferred mate, they should as well become less selective when potential rivals are present. Here, we investigated whether the presence of bystanders modifies male mating preferences when the risk of sperm competition is low, by carrying out mate-choice experiments with male zebra finches (Taeniopygia guttata) whose preferences for two females were measured twice: with and without an audience. We found that the presence of potential rivals had no effect on the males’ choosiness. However, with an audience, they spent more time with the female that was considered as the less attractive one in the control condition. These findings support the hypothesis that monogamous males alter their mate choice decisions in the presence of a male audience to reduce the risk of remaining unpaired. Thus, our results indicate that several explanations can account for the changes in male preferences due to the presence of competitors and highlight the importance of assessing the relative role of each mechanism potentially involved, to be able to make conclusions about the effect of an audience on signal evolution. PMID:22916298

Dubois, Frederique; Belzile, Alexandra

2012-01-01

186

Adrenocortical responses in zebra finches (Taeniopygia guttata): individual variation, repeatability, and relationship to phenotypic quality.  

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Although individual variation is a key requirement for natural selection, little is known about the magnitude and patterns of individual variation in endocrine systems or the functional significance of that variation. Here we describe (1) the extent and repeatability of inter-individual variation in adrenocortical responses and (2) its relationship to sex-specific phenotypic quality, such as song duration and frequency and timing of egg laying. We measured adrenocortical responses to a standardized stressor in zebra finches (Taeniopygia guttata) at two life history stages: approximately day 16 (nestlings) and 3 months of age (sexually mature adults). Subsequently, we assessed phenotypic (reproductive) quality of all individuals as adults. Marked inter-individual variation in the adrenocortical response was seen in both sexes and ages, e.g., stress-induced corticosterone ranged from 2.2 to 62.5 ng/mL in nestlings and 5.0-64.0 ng/mL in adults. We found sex differences in (a) inter-individual variation in the adrenocortical response, (b) repeatability, and (c) relationships between corticosterone levels and phenotypic quality. In males, variation in nestling corticosterone was weakly but positively correlated with brood size and negatively correlated with nestling mass (though this relationship was dependent on one individual). There was no significant correlation of adrenocortical responses between two stages in males and adult phenotypic quality was significantly correlated only with adult corticosterone levels. In contrast, in females there was no relationship between nestling corticosterone and brood size or mass but adrenocortical response was repeatable between two stages (r2=0.413). Phenotypic quality of adult females was correlated with nestling baseline and adrenocortical response. PMID:18221739

Wada, Haruka; Salvante, Katrina G; Stables, Christine; Wagner, Emily; Williams, Tony D; Breuner, Creagh W

2008-03-01

187

Zebra Mussel Farming in the Szczecin (Oder Lagoon: Water-Quality Objectives and Cost-Effectiveness  

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Full Text Available The Oder (Szczecin Lagoon in the southern Baltic Sea is a heavily eutrophicated and degraded coastal ecosystem. We applied a systems approach framework to critically evaluate whether existing water-management measures achieve water-quality objectives for the river and lagoon systems. Our simulations reveal that the existing water-quality objectives for the river and the coastal waters are not sufficiently complementary. We suggest new water-quality threshold concentrations, which are in agreement with the European Water Framework Directive, and we calculate acceptable maximum nutrient loads for the Oder River. These calculations suggest that external nutrient-load reductions in the river basin alone seem insufficient to achieve good water quality in the lagoon. A comprehensive eutrophication management approach should also include internal nutrient-retention and nutrient-removal measures in the lagoon. We focus on mussel farming, i.e., that of zebra mussels, Dreissena polymorpha, because they are efficient in removing nutrients and improving water transparency in the Oder Lagoon. For this purpose, the ecosystem model ERGOM is extended by a mussel module and an economic model. The economic model describes costs and benefits of mussel cultivation depending on the the farm size. We included additional potential sources of income such as water-quality tax or emission certificates. The simulations show that mussel farming in the lagoon is a suitable supportive measure and, at a load-reduction target of 50% or more, it is a cost-efficient measure for removing nutrients and for implementing the Baltic Sea Action Plan. In the Oder Lagoon, mussel farming could potentially remove nearly 1000 t of N (70 t of P/year, or about 2% of the present N and P loads, and it would have the additional benefit of improving water transparency.

Thomas Neumann

2012-06-01

188

No heightened condition dependence of zebra finch ornaments--a quantitative genetic approach.  

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The developmental stress hypothesis offers a mechanism to maintain honesty of sexually selected ornaments, because only high quality individuals will be able to develop full ornamentation in the face of stress during early development. Experimental tests of this hypothesis have traditionally involved the manipulation of one aspect of the rearing conditions and an examination of effects on adult traits. Here, we instead use a statistically powerful quantitative genetic approach to detect condition dependence. We use animal models to estimate environmental correlations between a measure of early growth and adult traits. This way, we could make use of the sometimes dramatic differences in early growth of more than 800 individually cross-fostered birds and measure the effect on a total of 23 different traits after birds reached maturity. We find strong effects of environmental growth conditions on adult body size, body mass and fat deposition, moderate effects on beak colour in both sexes, but no effect on song and plumage characters. Rather surprisingly, there was no effect on male attractiveness, both measured in mate choice trials and under socially complex conditions in aviaries. There was a trend for a positive effect of good growth conditions on the success at fertilizing eggs in males breeding in aviaries whereas longevity was not affected in either sex. We conclude that zebra finches are remarkably resilient to food shortage during growth and can compensate for poor growth conditions without much apparent life-history trade-offs. Our results do not support the hypothesis that sexually selected traits show heightened condition dependence compared to nonsexually selected traits. PMID:20074304

Bolund, E; Schielzeth, H; Forstmeier, W

2010-03-01

189

Identification of the molecules involved in zebra mussel (Dreissena polymorpha) hemocytes host defense.  

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The invasion of North American waterbodies by the zebra mussel (Dreissena polymorpha) has caused ecological catastrophies in North America. Unfortunately, little is known about this nuisance mollusk and its host defense mechanisms. In this study, 32 expressed sequence tags (ESTs) associated with hemocyte stimulation were obtained from a suppression subtractive hybridization (SSH) cDNA library. This SSH-cDNA library was produced by using a cDNA library of naïve hemocytes as the driver and a cDNA library of hemocytes stimulated with a mixture of microbial antigens namely, lipopolysacchride (LPS), peptidoglycan (PGN), and zymosan (ZYM), as the tester. The driver cDNA was subtracted from the tester to increase the relative abundance of the cDNAs that were induced by stimulations. The putative function of 27 ESTs were obtained by using the homologue searching program BLASTx and BLASTn. Four ESTs encoding the protein product homologous to matrilin (Matrn, AM503947), heat shock protein 70 (HSP70, EU835391), seryl-tRNA synthetase (STS, AM503950), and glycine-rich protein (GRP, AM502279) were selected for a subsequent study using quantitative PCR (qPCR) assays with the RNA extracted from hemocytes stimulated with LPS alone. The results of quantitative PCR with stimulated hemocyte RNA demonstrated that the four candidate genes were upregulated by LPS stimulation. The expression levels of both HSP70 and Matrn genes between naïve and 1-h stimulated hemocyte samples are the most significant with 2.78 and 2.20 fold increases, respectively. The significant changes of GRP and STS genes were observed after 2-h stimulation. The phylogenetic analysis of HSP70 molecule indicated that this protein is phylogenetically close to the HSP70 identified from other mollusks. This study shed light on hemocyte-mediated host defense mechanisms of D. polymorpha. PMID:19482094

Xu, Wei; Faisal, Mohamed

2009-09-01

190

A review of Zebra techniques for the measurement of reactivity parameters, reaction rate ratios and spectra  

International Nuclear Information System (INIS)

The paper describes the techniques devised for measurements of reactivity parameters, within-cell reaction rates and neutron energy spectra in plutonium fuelled assemblies in Zebra. Results of such measurements have played a major role in the adjustment studies leading to the new FGL5 Library. Emphasis is placed on the assessment of experimental and analytical errors which are compared with target errors set by reactor physics considerations. K-effective values are found from careful analysis of critical mass with due account of composition and dimensional uncertainties. K-infinity is obtained from cell worth measurements in small driven test-regions. Buckling values are derived from analysis of fission scan data by the experimental adjoint method using diffusion and transport theory. Foil activation, fission chamber and solid state track recorder techniques have been applied to fission rate measurements with Pu239, U235 and U238. Capture rates in U238 are obtained from thermal comparison and absolute counting methods. Spectrum measurements have been made by a range of techniques covering a total energy range from 100 ev to 6 Mev. These include time-of-flight, proton recoil, lithium-6 and double scintillator spectrometers. Comparison of different techniques over their range of overlap provide a check on the internal error estimation. Only the time-of-flight method is applicable below 5 Kev and improvements to various aspects of this technique are still needed to obtain the desired confidence in the Doppler region. Data from the spectrum measurements have been input to the LSQ adjustment scheme leading to the production of the FGL5 Data Library, the information being presented in the form of ratios of flux in adjacent groups of a 10 group set. Spectrum predictions before and after the adjustment process are compared. (author)

191

Vegetation description of the Doornhoek section of the Mountain Zebra National Park (MZNP, South Africa  

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Full Text Available The Mountain Zebra National Park (MZNP has been extended over the last couple of years. One of the newly procured areas is the Doornhoek section, which had been adjacent to the park. To develop scientifically sound management programmes for conservation areas, it is essential that an inventory of their natural resources be undertaken. The aim of this study was to classify, describe and map the vegetation of the Doornhoek section of the park. The floristic data were analysed in accordance with the Braun-Blanquet procedures using the BBPC suite. The data analysis resulted in the identification of eight communities, which can be grouped into seven major community types (Rhus lucida–Buddleja glomerata Shrubland, Rhigozum obovatum–Rhus longispina Shrubland, Helichrysum dregeanum–Aristida diffusa Grassland, Pentzia globosa–Enneapogon scoparius Grassland, Aristida adscensionus–Pentzia globosa Grassland, Cadaba aphylla–Acacia karroo Woodland and Lycium oxycarpum–Acacia karroo Woodland. Four of these communities occur on the higher-lying plateau, mid-slope and crest areas, while the other four communities are located on the lower-lying mid-plateau and foot slope, along drainage lines and in valley-bottom areas. The description of the plant communities, together with the vegetation map, can serve as a basis for formulating a management programme for the larger park. Although sections of Doornhoek have been overgrazed and degraded in the past, its recent addition to the MZNP contributes to the available habitat preferred by large herbivores, such as valley bottoms, foot-slopes and plateaux.

Leslie R. Brown

2008-05-01

192

Vegetation description of the Doornhoek section of the Mountain Zebra National Park (MZNP), South Africa  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The Mountain Zebra National Park (MZNP) has been extended over the last couple of years. One of the newly procured areas is the Doornhoek section, which had been adjacent to the park. To develop scientifically sound management programmes for conservation areas, it is essential that an inventory of t [...] heir natural resources be undertaken. The aim of this study was to classify, describe and map the vegetation of the Doornhoek section of the park. The floristic data were analysed in accordance with the Braun-Blanquet procedures using the BBPC suite. The data analysis resulted in the identification of eight communities, which can be grouped into seven major community types (Rhus lucida-Buddleja glomerata Shrubland, Rhigozum obovatum-Rhus longispina Shrubland, Helichrysum dregeanum-Aristida diffusa Grassland, Pentzia globosa-Enneapogon scoparius Grassland, Aristida adscensionus-Pentzia globosa Grassland, Cadaba aphylla-Acacia karroo Woodland and Lycium oxycarpum-Acacia karroo Woodland). Four of these communities occur on the higher-lying plateau, mid-slope and crest areas, while the other four communities are located on the lower-lying mid-plateau and foot slope, along drainage lines and in valley-bottom areas. The description of the plant communities, together with the vegetation map, can serve as a basis for formulating a management programme for the larger park. Although sections of Doornhoek have been overgrazed and degraded in the past, its recent addition to the MZNP contributes to the available habitat preferred by large herbivores, such as valley bottoms, foot-slopes and plateaux.

Hugo, Bezuidenhout; Leslie R., Brown.

193

GABA immunoreactivity in auditory and song control brain areas of zebra finches.  

Science.gov (United States)

Inhibitory transmission is critical to sensory and motor processing and is believed to play a role in experience-dependent plasticity. The main inhibitory neurotransmitter in vertebrates, GABA, has been implicated in both sensory and motor aspects of vocalizations in songbirds. To understand the role of GABAergic mechanisms in vocal communication, GABAergic elements must be characterized fully. Hence, we investigated GABA immunohistochemistry in the zebra finch brain, emphasizing auditory areas and song control nuclei. Several nuclei of the ascending auditory pathway showed a moderate to high density of GABAergic neurons including the cochlear nuclei, nucleus laminaris, superior olivary nucleus, mesencephalic nucleus lateralis pars dorsalis, and nucleus ovoidalis. Telencephalic auditory areas, including field L subfields L1, L2a and L3, as well as the caudomedial nidopallium (NCM) and mesopallium (CMM), contained GABAergic cells at particularly high densities. Considerable GABA labeling was also seen in the shelf area of caudodorsal nidopallium, and the cup area in the arcopallium, as well as in area X, the lateral magnocellular nucleus of the anterior nidopallium, the robust nucleus of the arcopallium and nidopallial nucleus HVC. GABAergic cells were typically small, most likely local inhibitory interneurons, although large GABA-positive cells that were sparsely distributed were also identified. GABA-positive neurites and puncta were identified in most nuclei of the ascending auditory pathway and in song control nuclei. Our data are in accordance with a prominent role of GABAergic mechanisms in regulating the neural circuits involved in song perceptual processing, motor production, and vocal learning in songbirds. PMID:17466487

Pinaud, Raphael; Mello, Claudio V

2007-09-01

194

Cloning, Expression and Characterization of Zebra Fish Ferroportin in Hek 293T Cell Line  

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Full Text Available Background: Ferroportin (Fpn, a regulator of iron homeostasis is a conserved membrane protein that exports iron across the enterocytes, macrophages and hepatocytes into the blood circulation. Fpn has also critical influence on survival of microorganisms whose growth is dependent upon iron, thus preparation of Fpn is needed to study the role of iron in immunity and pathogenesis of micoorganisms.Methods: To prepare and characterize a recombinant ferroportin, total RNA was extracted from Indian zebrafish duodenum, and used to synthesize cDNA by RT-PCR. PCR product was first cloned in Topo TA vector and then subcloned into the GFP expression vector pEGFP-N1. The final resulted plasmid (pEGFP-ZFpn was used for expression of Fpn-EGFP protein in Hek 293T cells.Results: The expression was confirmed by appearance of fluorescence in Hek 293 T cells. Recombinant Fpn was further characterized by submission of its predicted amino acid sequences to the TMHMM V2.0 prediction server (hidden Markov model, NetOGlyc 3.1 and NetNGlyc 3.1 servers. The obtained Fpn from indian zebrafish also contained eight transmembrane domains with N- and C-termini inside the cytoplasm and harboured 78 O-glycosylated amino acids.Conclusion: The recombinant Fpn from Indian zebra fish was successfully expressed in Hek 293 cell line. Although the discrepancy in two amino acids was observed in our produced Fpn and resulted in an additional O-glycosylation site, but had no effect on the topology of the protein compared to other Fpn described by other researchers. Therefore this construct can be used in future iron studies.

A Memarnejadian

2012-01-01

195

Is the Rate of Metabolic Ageing and Survival Determined by Basal Metabolic Rate in the Zebra Finch?  

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The relationship between energy metabolism and ageing is of great interest because aerobic metabolism is the primary source of reactive oxygen species which is believed to be of major importance in the ageing process. We conducted a longitudinal study on captive zebra finches where we tested the effect of age on basal metabolic rate (BMR), as well as the effect of BMR on the rate of metabolic ageing (decline in BMR with age) and survival. Basal metabolic rate declined with age in both sexes after controlling for the effect of body mass, indicating a loss of functionality with age. This loss of functionality could be due to accumulated oxidative damage, believed to increase with increasing metabolic rate, c.f. the free radical theory of ageing. If so, we would expect the rate of metabolic ageing to increase and survival to decrease with increasing BMR. However, we found no effect of BMR on the rate of metabolic ageing. Furthermore, survival was not affected by BMR in the males. In female zebra finches there was a tendency for survival to decrease with increasing BMR, but the effect did not reach significance (Pfinches. PMID:25265184

R?nning, Bernt; Moe, B?rge; Berntsen, Henrik H.; Noreen, Elin; Bech, Claus

2014-01-01

196

Growth and atrophy of neurons labeled at their birth in a song nucleus of the zebra finch  

International Nuclear Information System (INIS)

The robust nucleus of the archistriatum (RA) is one of the forebrain nuclei that control song production in birds. In the zebra finch (Poephila guttata), this nucleus contains more and larger neurons in the male than in the female. A single injection of tritiated thymidine into the egg on the 6th or 7th day of incubation resulted in labeling of many RA neurons with tritium. The size of tritium-labeled neurons and the tissue volume containing them did not differ between the sexes at 15 days after hatching. In the adult brain, tritium-labeled neurons and the tissue volume containing them were much larger in the male than in the female. Also, tritium-labeled RA neurons were large in females which received an implant of estrogen immediately after hatching. The gender differences in the neuron size and nuclear volume of the zebra finch RA are, therefore, due not to the replacement of old neurons by new ones during development but to the growth and atrophy of neurons born before hatching. Similarly, the masculinizing effects of estrogen on the female RA are due not to neuronal replacement but to the prevention of atrophy and promotion of growth in preexisting neurons

197

Effects of lethal and sublethal concentrations of the herbicide, triclopyr butoxyethyl ester, in the diet of zebra finches.  

Science.gov (United States)

Lethal and sublethal effects of dietary triclopyr butoxyethyl ester (TBEE) on zebra finches (Poephila guttata Gould) were determined in laboratory experiments conducted between 8 January and 1 May 1991. The 8-day median lethal dietary concentration, LC50 (95% confidence interval), of TBEE to zebra finches was 1,923 (1,627 to 2,277) mg/kg. In the sublethal effects experiment, when birds were exposed to 500 mg/kg TBEE in the diet for 29 days, food consumption and body weight were significantly depressed (P 0.05). Perch-hopping activity was depressed relative to controls in the 500 mg/kg group, and elevated in the 150 mg/kg group, but neither of these differences was significantly (P > 0.05). Disappearance of TBEE residues from treated seeds over the 29 day experimental period followed an exponential decay model, with half-lives in the order of 15 to 18 days. On the basis of our observation that TBEE had no significant adverse effects at a concentration greater than the maximum expected environmental concentration, we propose that forestry applications of triclopyr at registered dosage rates pose little risk to wild songbirds. PMID:7933272

Holmes, S B; Thompson, D G; Wainio-Keizer, K L; Capell, S S; Staznik, B

1994-07-01

198

Effects of early developmental conditions on innate immunity are only evident under favourable adult conditions in zebra finches  

Science.gov (United States)

Long-term effects of unfavourable conditions during development can be expected to depend on the quality of the environment experienced by the same individuals during adulthood. Yet, in the majority of studies, long-term effects of early developmental conditions have been assessed under favourable adult conditions only. The immune system might be particularly vulnerable to early environmental conditions as its development, maintenance and use are thought to be energetically costly. Here, we studied the interactive effects of favourable and unfavourable conditions during nestling and adult stages on innate immunity (lysis and agglutination scores) of captive male and female zebra finches ( Taeniopygia guttata). Nestling environmental conditions were manipulated by a brood size experiment, while a foraging cost treatment was imposed on the same individuals during adulthood. This combined treatment showed that innate immunity of adult zebra finches is affected by their early developmental conditions and varies between both sexes. Lysis scores, but not agglutination scores, were higher in individuals raised in small broods and in males. However, these effects were only present in birds that experienced low foraging costs. This study shows that the quality of the adult environment may shape the long-term consequences of early developmental conditions on innate immunity, as long-term effects of nestling environment were only evident under favourable adult conditions.

de Coster, Greet; Verhulst, Simon; Koetsier, Egbert; de Neve, Liesbeth; Briga, Michael; Lens, Luc

2011-12-01

199

Separating natural from anthropogenic causes of impairment in Zebra mussel (Dreissena polymorpha) populations living across a pollution gradient.  

Science.gov (United States)

The relationship between the reproductive stage, the total lipid content and eight broadly used biochemical stress responses were used to assess seasonal and pollutant effects across eleven different zebra mussel (Dreissena polymorpha) populations from the Ebro and Mijares river basin, Spain. Biochemical markers included superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione S transferase (GST), multixenobiotic transporter activity (MXR), lactate dehydrogenase (LDH), lipid peroxidation (LPO) and single strand DNA breaks. Principal component analyses of zebra mussel responses across an annual cycle, showed a marked gonad stage component in total lipid content and biochemical responses. The same response pattern was observed across the populations sampled along a broad geographical and pollution gradient. Population differences on the gonad developmental stage were highly correlated with most of the measured responses and unrelated with the pollution gradient. Conversely, bioaccumulation of organic and inorganic contaminant residues was more related to pollution sources than with the reproductive cycle. These results indicate that the reproductive cycle is the major factor affecting the temporal and spatial variation of the studied markers in D. polymorpha. PMID:24742819

Faria, Melissa; Ochoa, Victoria; Blázquez, Mercedes; Juan, Maria Fernandes San; Lazzara, Raimondo; Lacorte, Silvia; Soares, Amadeu M V M; Barata, Carlos

2014-07-01

200

QTL linkage mapping of zebra finch beak color shows an oligogenic control of a sexually selected trait.  

Science.gov (United States)

Mate choice based on sexual ornaments can impose strong selection, which raises the question of how genetic variation in ornaments is maintained. One mechanism that has been proposed is genic capture. If ornament expression is influenced by general condition and condition is under polygenic control, selection will be inefficient in removing genetic variation. Here we analyze whether the genetic architecture of beak color in a population of zebra finches supports this hypothesis. Zebra finch beak color is commonly assumed to be under strong selection by mate choice, although some of the evidence is ambiguous. We show that beak redness has a heritability of 34% in our population and that it is strongly genetically correlated between the sexes, suggesting that it is largely controlled by the same genes in males and females. We mapped variation in beak redness based on 1404 single-nucleotide polymorphism (SNP) markers genotyped in a large pedigree. We find evidence for linkage on four chromosomes (Tgu1, Tgu5, Tgu13, Tgu21), which together explain a large part of the additive genetic variance. Our finding of genomic regions with major additive effects is not consistent with directional selection and genic capture, but rather suggests a role of antagonistic pleiotropy in maintaining genetic variation. PMID:22220861

Schielzeth, Holger; Kempenaers, Bart; Ellegren, Hans; Forstmeier, Wolfgang

2012-01-01

 
 
 
 
201

A cost-benefit analysis of preventative management for zebra and quagga mussels in the Colorado-Big Thompson System  

Science.gov (United States)

Zebra and quagga mussels are fresh water invaders that have the potential to cause severe ecological and economic damage. It is estimated that mussels cause $1 billion dollars per year in damages to water infrastructure and industries in the United States (Pimentel et al., 2004). Following their introduction to the Great Lakes in the late 1980s, mussels spread rapidly throughout the Mississippi River Basin and the Eastern U.S. The mussel invasion in the West is young. Mussels were first identified in Nevada in 2007, and have since been identified in California, Arizona, Colorado, Utah, and Texas. Western water systems are very different from those found in the East. The rapid spread of mussels through the eastern system was facilitated by connected and navigable waterways. Western water systems are less connected and are characterized by man-made reservoirs and canals. The main vector of spread for mussels in the West is overland on recreational boats (Bossenbroek et al., 2001). In response to the invasion, many western water managers have implemented preventative management programs to slow the overland spread of mussels on recreational boats. In Colorado, the Colorado Department of Wildlife (CDOW) has implemented a mandatory boat inspection program that requires all trailered boats to be inspected before launching in any Colorado water body. The objective of this study is to analyze the costs and benefits of the CDOW boat inspection program in Colorado, and to identify variables that affect the net benefits of preventative management. Predicting the potential economic benefits of slowing the spread of mussels requires integrating information about mussel dispersal potential with estimates of control costs (Keller et al., 2009). Uncertainty surrounding the probabilities of establishment, the timing of invasions, and the damage costs associated with an invasion make a simulation model an excellent tool for addressing "what if" scenarios and shedding light on the net benefits of preventative management strategies. This study builds a bioeconomic simulation model to predict and compare the expected economic costs of the CDOW boat inspection program ot the benefits of reduced expected control costs to water conveyance systems, hydropower generation stations, and minicipal water treatment facilities. The model is based on a case study water delivery and storage system, the Colorado-Big Thompson system. The Colorado-Big Thomspon system is an excellent example of water systems in the Rocky Mountain West. The system is nearly entirely man-made, with all of its reservoirs and delivery points connected via pipelines, tunnels, and canals. The structures and hydropower systems of the Colorado-Big Thompson system are common to other western storage and delivery systems, making the methods and insight developed from this case study transferal to other western systems. The model developed in this study contributes to the bioeconomic literature in several ways. Foremost, the model predicts the spread of dreissena mussels and associated damage costs for a connected water system in the Rocky Mountain West. Very few zebra mussel studies have focused on western water systems. Another distinguishing factor is the simultaneous consideration of spread from propagules introduced by boats and by flows. Most zebra mussel dispersal models consider boater movement patterns combined with limnological characteristics as predictors of spread. A separate set of studies have addressed mussel spread via downstream flows. To the author's knowledge, this is the first study that builds a zebra mussel spread model that specifically accounts for propagule pressure from boat introductions and from downstream flow introductions. By modeling an entire connected system, the study highlights how the spatial layout of a system, and the risk of invasion within a system affect the benefits of preventative management. This report is presented in five chapters. The first chapter provides background information including a history of the zebra mussel invasion in the U.

Thomas, Catherine M.

2010-01-01

202

Mutations of amino acids in the DNA-recognition domain of Epstein-Barr virus ZEBRA protein alter its sub-nuclear localization and affect formation of replication compartments  

International Nuclear Information System (INIS)

ZEBRA, a transcription factor and DNA replication protein encoded by the Epstein-Barr virus (EBV) BZLF1 gene, plays indispensable roles in the EBV lytic cycle. We recently described the phenotypes of 46 single amino acid substitutions introduced into the DNA-recognition region of ZEBRA [Heston, L., El-Guindy, A., Countryman, J., Dela Cruz, C., Delecluse, H.J., and Miller, G. 2006]. The 27 DNA-binding-proficient mutants exhibited distinct defects in their ability to activate expression of the kinetic classes of viral genes. Four phenotypic variants could be discerned: wild-type, defective at activating Rta, defective at activating early genes, and defective at activating late genes. Here we analyze the distribution of ZEBRA within the nucleus and the localization of EA-D (the viral DNA polymerase processivity factor), an indicator of the development of replication compartments, in representatives of each phenotypic group. Plasmids encoding wild-type (WT) and mutant ZEBRA were transfected into 293 cells containing EBV-bacmids. WT ZEBRA protein was diffusely and smoothly distributed throughout the nucleus, sparing nucleoli, and partially recruited to globular replication compartments. EA-D induced by WT ZEBRA was present diffusely in some cells and concentrated in globular replication compartments in other cells. The distribution of ZEBRA and EA-D proteins was identical to WT following transfection of K188R, a mutant with a conservative change. The distribution of S186A mutant ZEBRA protein, defective for activation of Rta and EA-D, was identical to WT, except that the mutant ZEBRA was never found in globular compartments. Co-expression of Rta with S186A mutant rescued diffuse EA-D but not globular replication compartments. The most striking observation was that several mutant ZEBRA proteins defective in activating EA-D (R179A, K181A and A185V) and defective in activating lytic viral DNA replication and late genes (Y180E and K188A) were localized to numerous punctate foci. The speckled appearance of R179A and Y180E was more regular and clearly defined in EBV-positive than in EBV-negative 293 cells. The Y180E late-mutant induced EA-D, but prevented EA-D from localizing to globular replication compartments. These results show that individual amino acids within the basic domain influence localization of the ZEBRA protein and its capacity to induce EA-D to become located in mature viral replication compartments. Furthermore, these mutant ZEBRA proteins delineate several stages in the processes of nuclear re-organization which accompany lytic EBV replication

203

Mutations of amino acids in the DNA-recognition domain of Epstein-Barr virus ZEBRA protein alter its sub-nuclear localization and affect formation of replication compartments.  

Science.gov (United States)

ZEBRA, a transcription factor and DNA replication protein encoded by the Epstein-Barr virus (EBV) BZLF1 gene, plays indispensable roles in the EBV lytic cycle. We recently described the phenotypes of 46 single amino acid substitutions introduced into the DNA-recognition region of ZEBRA [Heston, L., El-Guindy, A., Countryman, J., Dela Cruz, C., Delecluse, H.J., and Miller, G. 2006]. The 27 DNA-binding-proficient mutants exhibited distinct defects in their ability to activate expression of the kinetic classes of viral genes. Four phenotypic variants could be discerned: wild-type, defective at activating Rta, defective at activating early genes, and defective at activating late genes. Here we analyze the distribution of ZEBRA within the nucleus and the localization of EA-D (the viral DNA polymerase processivity factor), an indicator of the development of replication compartments, in representatives of each phenotypic group. Plasmids encoding wild-type (WT) and mutant ZEBRA were transfected into 293 cells containing EBV-bacmids. WT ZEBRA protein was diffusely and smoothly distributed throughout the nucleus, sparing nucleoli, and partially recruited to globular replication compartments. EA-D induced by WT ZEBRA was present diffusely in some cells and concentrated in globular replication compartments in other cells. The distribution of ZEBRA and EA-D proteins was identical to WT following transfection of K188R, a mutant with a conservative change. The distribution of S186A mutant ZEBRA protein, defective for activation of Rta and EA-D, was identical to WT, except that the mutant ZEBRA was never found in globular compartments. Co-expression of Rta with S186A mutant rescued diffuse EA-D but not globular replication compartments. The most striking observation was that several mutant ZEBRA proteins defective in activating EA-D (R179A, K181A and A185V) and defective in activating lytic viral DNA replication and late genes (Y180E and K188A) were localized to numerous punctate foci. The speckled appearance of R179A and Y180E was more regular and clearly defined in EBV-positive than in EBV-negative 293 cells. The Y180E late-mutant induced EA-D, but prevented EA-D from localizing to globular replication compartments. These results show that individual amino acids within the basic domain influence localization of the ZEBRA protein and its capacity to induce EA-D to become located in mature viral replication compartments. Furthermore, these mutant ZEBRA proteins delineate several stages in the processes of nuclear re-organization which accompany lytic EBV replication. PMID:18937960

Park, Richard; Heston, Lee; Shedd, Duane; Delecluse, Henri-Jacques; Miller, George

2008-12-20

204

Spatio-temporal spawning and larval dynamics of a zebra mussel (Dreissena polymorpha) population in a North Texas Reservoir: implications for invasions in the southern United States  

Science.gov (United States)

Zebra mussels were first observed in Texas in 2009 in a reservoir (Lake Texoma) on the Texas-Oklahoma border. In 2012, an established population was found in a near-by reservoir, Ray Roberts Lake, and in June 2013, settled mussels were detected in a third north Texas reservoir, Lake Lewisville. An established population was detected in Belton Lake in September 2013. With the exception of Louisiana, these occurrences in Texas mark the current southern extent of the range of this species in the United States. Previous studies indicate that zebra mussel populations could be affected by environmental conditions, especially increased temperatures and extreme droughts, which are characteristic of surface waters of the southern and southwestern United States. Data collected during the first three years (2010–12) of a long-term monitoring program were analyzed to determine if spatio-temporal zebra mussel spawning and larval dynamics were related to physicochemical water properties in Lake Texoma. Reproductive output of the local population was significantly related to water temperature and lake elevation. Estimated mean date of first spawn in Lake Texoma was approximately 1.5 months earlier and peak veliger densities were observed two months earlier than in Lake Erie. Annual maximum veliger density declined significantly during the study period (p mussels in littoral zones. Veliger spatial distributions were associated with physicochemical stratification characteristics. Veligers were observed in the deepest oxygenated water after lake stratification, which occurred in late spring. Results of this study indicate environmental conditions can influence variability of population sizes and spatial distributions of zebra mussels along the current southern frontier of their geographic range. Although the future population size trajectory and geographic range are uncertain, increased temperatures and intermittent, extreme droughts likely will affect spatio-temporal dynamics of established populations if zebra mussels spread farther into the southern and southwestern United States.

Churchill, Christopher John

2013-01-01

205

Impacts of microcystins on the feeding behaviour and energy balance of zebra mussels, Dreissena polymorpha: a bioenergetics approach.  

Science.gov (United States)

Microcystins are produced by bloom-forming cyanobacteria and pose significant health and ecological problems. To investigate the impacts of these biotoxins on the physiology of the zebra mussels, Dreissena polymorpha, a series of short-term feeding experiments were conducted in the laboratory. We used five microalgal diets consisting of single-cell suspensions of the green algae, Chlorella vulgaris, the diatom, Asterionella formosa, the cryptophyte, Cryptomonas sp. and two strains of the toxic cyanobacterium, Microcystis aeruginosa (strains CCAP 1450/06 and CCAP 1450/10). A sixth diet was a mixture of the diatom and the CCAP 1450/10 cyanobacterial strain. The low-toxicity strain CCAP 1450/06 contained 7.4 microg l(-1) of the MC-LR variant while the very toxic strain CCAP 1450/10 contained 23.8 microg l(-1) of MC-LR and 82.9 microg l(-1) of MC-LF. A flow-through system was designed to measure the following feeding parameters: clearance, filtration, ingestion and absorption rates. Ultimately the scope for growth (SFG) was determined as a net energy balance. We observed that mussels cleared the cyanobacterial species containing MC-LF (mean+/-95% confidence interval) at a significant lower rate (498+/-82 ml h(-1) g(-1) for the single cell suspension and 663+/-100 ml h(-1) g(-1) for the mixture diet) than all of the non-toxic species and the cyanobacterium containing MC-LR (all above 1l h(-1) g(-1)). The same pattern was observed with all the feeding parameters, particularly absorption rates. Furthermore, MC-LF caused an acute irritant response manifested by the production of 'pseudodiarrhoea', unusually fluid pseudofaeces, rich in mucus and MC-LF-producing Microcystis cells, ejected through the pedal gape of the mussels. This overall response therefore demonstrates selective rejection of MC-LF-producing cyanobacteria by zebra mussels, enhancing the presence of the very toxic MC-LF-producing M. aeruginosa in mixed cyanobacterial blooms and in the benthos. Finally, we observed that the SFG (mean+/-95% confidence interval) of mussels feeding on M. aeruginosa containing MC-LF was significantly lower (34.0+/-18.8 J h(-1) g(-1) for the single cell suspension and 83.1+/-53.0 J h(-1) g(-1) for the mixture diet) than for mussels ingesting non-toxic diets, except for C. vulgaris (all above 200 J h(-1)g(-1)). This reveals a sublethal, stressful effect of microcystins (particularly MC-LF) on the feeding behaviour and energy balance of the zebra mussel. PMID:16911837

Juhel, G; Davenport, J; O'Halloran, J; Culloty, S C; O'Riordan, R M; James, K F; Furey, A; Allis, O

2006-10-12

206

Sex-specific effects of maternal immunization on yolk antibody transfer and offspring performance in zebra finches  

Science.gov (United States)

Trans-generational antibody transfer constitutes an important mechanism by which mothers may enhance offspring resistance to pathogens. Thus, differential antibody deposition may potentially allow a female to differentiate offspring performance. Here, we examined whether maternal immunization with sheep red blood cells (SRBC) prior to egg laying affects sex-specific yolk antibody transfer and sex-specific offspring performance in zebra finches (Taeniopygia guttata). We showed that immunized mothers deposit anti-SRBC antibodies into the eggs depending on embryo sex and laying order, and that maternal exposure to SRBC positively affects the body size of female, but not male offspring. This is the first study reporting sex-specific consequences of maternal immunization on offspring performance, and suggests that antibody transfer may constitute an adaptive mechanism of maternal favouritism. PMID:20667842

Martyka, Rafal; Rutkowska, Joanna; Cichon, Mariusz

2011-01-01

207

Phosphorus addition reverses the positive effect of zebra mussels (Dreissena polymorpha) on the toxic cyanobacterium, Microcystis aeruginosa.  

Science.gov (United States)

We tested the hypothesis that zebra mussels (Dreissena polymorpha) have positive effects on the toxin-producing cyanobacterium, Microcystis aeruginosa, at low phosphorus (P) concentrations, but negative effects on M. aeruginosa at high P, with a large-scale enclosure experiment in an oligotrophic lake. After three weeks, mussels had a significantly positive effect on M. aeruginosa at ambient P (total phosphorus, TP ?10 ?g L?¹), and a significantly negative effect at high P (simulating a TP of ?40 ?g L?¹ in lakes). Positive and negative effects were strong and very similar in magnitude. Thus, we were able to ameliorate a negative effect of Dreissena invasion on water quality (i.e., promotion of Microcystis) by adding P to water from an oligotrophic lake. Our results are congruent with many field observations of Microcystis response to Dreissena invasion across ecosystems of varying P availability. PMID:22507249

Sarnelle, Orlando; White, Jeffrey D; Horst, Geoffrey P; Hamilton, Stephen K

2012-07-01

208

A comparison of SNPs and microsatellites as linkage mapping markers: lessons from the zebra finch (Taeniopygia guttata  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Genetic linkage maps are essential tools when searching for quantitative trait loci (QTL. To maximize genome coverage and provide an evenly spaced marker distribution a combination of different types of genetic marker are sometimes used. In this study we created linkage maps of four zebra finch (Taeniopygia guttata chromosomes (1, 1A, 2 and 9 using two types of marker, Single Nucleotide Polymorphisms (SNPs and microsatellites. To assess the effectiveness and accuracy of each kind of marker we compared maps built with each marker type separately and with both types of marker combined. Linkage map marker order was validated by making comparisons to the assembled zebra finch genome sequence. Results We showed that marker order was less reliable and linkage map lengths were inflated for microsatellite maps relative to SNP maps, apparently due to differing error rates between the two types of marker. Guidelines on how to minimise the effects of error are provided. In particular, we show that when combining both types of marker the conventional process of building linkage maps, whereby the most informative markers are added to the map first, has to be modified in order to improve map accuracy. Conclusions When using multiple types and large numbers of markers to create dense linkage maps, the least error prone loci (SNPs rather than the most informative should be used to create framework maps before the addition of other potentially more error prone markers (microsatellites. This raises questions about the accuracy of marker order and predicted recombination rates in previous microsatellite linkage maps which were created using the conventional building process, however, provided suitable error detection strategies are followed microsatellite-based maps can continue to be regarded as reasonably reliable.

Birkhead Tim R

2010-04-01

209

Cellular energy allocation in zebra mussels exposed along a pollution gradient: linking cellular effects to higher levels of biological organization  

International Nuclear Information System (INIS)

Organisms exposed to suboptimal environments incur a cost of dealing with stress in terms of metabolic resources. The total amount of energy available for maintenance, growth and reproduction, based on the biochemical analysis of the energy budget, may provide a sensitive measure of stress in an organism. While the concept is clear, linking cellular or biochemical responses to the individual and population or community level remains difficult. The aim of this study was to validate, under field conditions, using cellular energy budgets [i.e. changes in glycogen-, lipid- and protein-content and mitochondrial electron transport system (ETS)] as an ecologically relevant measurement of stress by comparing these responses to physiological and organismal endpoints. Therefore, a 28-day in situ bioassay with zebra mussels (Dreissena polymorpha) was performed in an effluent-dominated stream. Five locations were selected along the pollution gradient and compared with a nearby (reference) site. Cellular Energy Allocation (CEA) served as a biomarker of cellular energetics, while Scope for Growth (SFG) indicated effects on a physiological level and Tissue Condition Index and wet tissue weight/dry tissue weight ratio were used as endpoints of organismal effects. Results indicated that energy budgets at a cellular level of biological organization provided the fastest and most sensitive response and energy budgets are a relevant currency to extrapolate cellular effects to higher leveltrapolate cellular effects to higher levels of biological organization within the exposed mussels. - Exposure of zebra mussels along a pollution gradient has adverse effects on the cellular energy allocation, and results can be linked with higher levels of biological organization

210

Cytoarchitectonic organization and morphology of cells of the field L complex in male zebra finches (Taenopygia guttata).  

Science.gov (United States)

The organization of the field L complex, a thalamorecipient auditory region in the telencephalon of birds, was examined in Nissl and Golgi preparations of male zebra finches (Taenopygia guttata). The field L complex comprises five cytoarchitectonic subdivisions: L1, L2a, L2b, L3, and L, although the border between L and L2b is not distinct. L2a is a plate extending dorsocaudally from the dorsal medullary lamina in the caudal neostriatum. L1 lies on the anterodorsal border and L3 lies on the posteroventral border of L2a. L, the area designated "field L" by Rose (J. Psychol. Neurol., 1914, 2:278-352), forms the medial and posterior borders of the field L complex. L2b is a thick band that forms the dorsal and dorsolateral boundary of the field L complex and is continuous with L medially. Nucleus interface (NIf) is a nucleus that lies between L2a and L1 near the lateral edge of the complex. The four types of Golgi stained neurons that occur in the zebra finch field L complex correspond to those described for the European starling (Sturnus vulgaris). Additionally, type 3 neurons are subdivided into "unoriented" neurons with spherical dendritic fields and "oriented" neurons with bipolar dendritic fields. NIf contains a distinct class of neurons that have large somata with both thick and thin spiny dendrites. The distribution of Golgi cell types between the subdivisions of the field L complex corresponds to the morphology of cells seen in Nissl material. Type 3 oriented cells are found almost exclusively within L2a. L3 has significantly greater numbers of the largest cells (type 1) and significantly smaller numbers of the smallest cells (type 4) than does L1. There are no significant differences in the distribution of Golgi stained cells between L2b and L. PMID:1447407

Fortune, E S; Margoliash, D

1992-11-15

211

Influence of ortho-substitution homolog group on polychlorobiphenyl bioaccumulation factors and fugacity ratios in plankton and zebra mussels (Dreissena polymorpha)  

Energy Technology Data Exchange (ETDEWEB)

The accumulation of a set of non- and mono-ortho (coplanar) PCB congeners in aquatic ecosystems is of interest due to their dioxin-like toxicities. Chemical properties (octanol-water partition coefficients) suggest that the coplanar congeners may accumulate in organisms to a greater extent than homologs with greater ortho substitution. The authors analyzed a set of 65 PCB congeners with zero to four ortho-chlorines from seven homolog groups in water, suspended particulate matter, and zebra mussels from Green Bay, Wisconsin, USA, on four dates throughout the ice-free season. The suspended particulate matter was separated by size and characterized as phytoplankton or zooplankton using diagnostic carotenoid pigments and light microscopy. Median bioconcentration factors (BCFs) for accumulation from water by phytoplankton and bioaccumulation factors (BAFs) for accumulation from water plus food by zooplankton and zebra mussels ranged from 1 x 10{sup 4} to 1 x 10{sup 6} and were generally the greatest for the tetra- to heptachlorobiphenyls. The average coplanar congener BCFs and BAFs for accumulation from water by phytoplankton, zooplankton, and zebra mussels for the tri-, tetra-, and pentachlorobiphenyls were 54% larger than corresponding values for their homologs. Biomagnification factors (BMFs) of the tetra-, penta-, and hexachlorobiphenyls between zooplankton and zebra mussels and their food source, phytoplankton, typically ranged between 1 and 10, but the average coplanar congener BMFs were 25% less than values for their corresponding homologs. The tendency for coplanar congeners to accumulate to a lesser extent between trophic levels was not as large as their tendency to accumulate from water to a greater extent. Based on accumulation factors, the authors conclude that the dioxin-like tetra- and pentachlorobiphenyls generally accumulate in the phytoplankton, zooplankton, and zebra mussels of the Green Bay ecosystem to a greater extent than other congeners. Fugacity ratios suggest that, in phytoplankton and zooplankton, homolog concentrations were below equilibrium with water throughout the field season, particularly for the more chlorinated groups, but that concentrations in zebra mussels were at or above equilibrium with water.

Willman, E.J.; Manchester-Neesvig, J.B.; Agrell, C.; Armstrong, D.E.

1999-07-01

212

Metabolic programming of zebra fish Danio rerio uncovered. Physiological performance as explained by dynamic energy budget theory and life-cycle consequence of uranium induced perturbations  

International Nuclear Information System (INIS)

The aim of this dissertation is to characterize the toxicity of uranium on the metabolism of zebra fish, nio rerio. The first three chapters of this manuscript are dedicated to characterizing the blank metabolism of zebra fish. I used the Dynamic Energy Budget (deb) theory for this characterisation; it is presently the only theory that covers the full life cycle of the organism and quantifies feeding, assimilation, growth, reproduction, maturation, maintenance and ageing. Any metabolic effect of uranium should appear as effects on one or more of these fundamental processes. Since the life span of zebra fish is some four and a half years, and larger individuals respond slower to chemical stress, the focus was on the early life stages. Considerable breakthroughs in the quantification of zebra fish development, growth and reproduction have been made. It turned out the zebra fish accelerates its metabolism after birth till metamorphosis, when acceleration ceases. This process is seen in some, but not all, species of fish. Another striking conclusion was that somatic maintenance was much higher than is typical for fish. We don't yet have an explanation for this funding. Further it turned out that the details of reproduction matter: allocation to reproduction (in adults) accumulates in a reproduction buffer and this buffer is used to prepare batches of eggs. We needed to detail this preparation process to understand how zebra fish can eliminate uranium via eggs. Deb theory specifies that a particular developmental stage (birth, metamorphosis, puberty) is reached at specified levels of maturity. For different temperatures and food levels, that can occur at different ages and body sizes. We extended this idea to include all the described morphologically defined developmental stages of the zebra fish in the literature; the observed variations in ages and body sizes can now be explained by deb theory. To test if deb theory can also explain perturbations of maturation, we studied developmental patterns in two types of taxonomically related frog species of similar body size. One type shows a typical developmental pattern as embryo, feeding tadpole and juvenile frog. The other type shows, after hatching, but before birth (= start of feeding) a significant acceleration of maturation, which is visible as an increased respiration and retarded growth, with big effects on size at a given developmental stage. This acceleration is reduced after metamorphosis but compared to the standard type of frog, it takes considerable time to catch up in growth. All these changes could be captured accurately with deb theory by a temporary change in a single parameter: the fraction of mobilised reserve that is allocated to somatic maintenance plus growth, as opposed to maturity maintenance plus maturation. The conclusion is that the observed perturbations of maturation and the age and size variations at various developmental stages provide strong support for how deb theory incorporates maturation. We not only required detail on maturation but also on starvation, especially in the early juvenile stages. The problem is that, according to deb theory, maintenance is paid from mobilised reserve, but when food is scarce or absent, reserve becomes depleted and maintenance can no longer be paid from mobilised reserve. We included more detail on what happens exactly under such conditions. More specifically we modelled the processes of rejuvenation and shrinking (of structure) and their consequence for hazard rate. We managed to capture observed size and survival trajectories of fish fry under controlled starving conditions. These processes are not only important to capture effects of uranium on feeding, but have a much wider ecological significance in field situations. As a result of my work, there is now a formal basis for understanding (and predicting) how the physiological performance of zebra fish relates to food intake. The model was used to detect uranium induced eco-physiological deviations from the blank. For this purpose we developed a dynamic model for

213

No Band Color Effects on Male Courtship Rate or Body Mass in the Zebra Finch: Four Experiments and a Meta-Analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Replication of experiments is essential for distinguishing real effects from type 1 errors and idiosyncrasies. One of the most replicated experiments in behavioral ecology is the presumed manipulation of male attractiveness in zebra finches by adding red or green color bands. Red-banded males were found to have higher fitness than green-banded males, and most empirical evidence suggests that this effect is mediated by female mating preferences rather than by male-male competition. A recent st...

Seguin, Aurelie; Forstmeier, Wolfgang

2012-01-01

214

The impact of zebra mussel (Dreissena polymorpha) periostracum and biofilm cues on habitat selection by a Ponto-Caspian amphipod Dikerogammarus haemobaphes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dikerogammarus haemobaphes is one of several Ponto-Caspian gammarids invading Europe in recent decades. Previously, it exhibited active preferences for habitats associated with another Ponto-Caspian alien, zebra mussel. Now we tested gammarid preferences for living mussels and their empty shells with biofilm and/or periostracum present or absent, to find the exact cues driving gammarid responses. We observed a strong preference of gammarids for biofilmed shells, even if the biofilm was rel...

Kobak, Jaros?aw; Kakareko, Tomasz; Jermacz, ?ukasz; Poznan?ska, Ma?gorzata

2013-01-01

215

The ecology and impact of the invasion of Lake Ontario by the zebra mussel (Dreissena polymorpha) and quagga mussel (D. bugensis)  

Science.gov (United States)

In this chapter we present a detailed description of the zebra and quagga mussel invasion in Lake Ontario, with specific emphasis on: (1) the development of the Dreissena populations in Lake Ontario, (2) previously unreported data from 1997 and 1998 for Dreissena populations at Nine-Mile Point in Lake Ontario, (3) factors influencing dreissenid development in Lake Ontario, and (4) the effects of dreissenid colonization on the biota of the Lake Ontario ecosystem.

Negley, T.L.; Mills, E.L.; Baldwin, B.; O'Gorman, R.; Owens, R.W.

2003-01-01

216

pocketZebra: a web-server for automated selection and classification of subfamily-specific binding sites by bioinformatic analysis of diverse protein families  

Science.gov (United States)

The new web-server pocketZebra implements the power of bioinformatics and geometry-based structural approaches to identify and rank subfamily-specific binding sites in proteins by functional significance, and select particular positions in the structure that determine selective accommodation of ligands. A new scoring function has been developed to annotate binding sites by the presence of the subfamily-specific positions in diverse protein families. pocketZebra web-server has multiple input modes to meet the needs of users with different experience in bioinformatics. The server provides on-site visualization of the results as well as off-line version of the output in annotated text format and as PyMol sessions ready for structural analysis. pocketZebra can be used to study structure–function relationship and regulation in large protein superfamilies, classify functionally important binding sites and annotate proteins with unknown function. The server can be used to engineer ligand-binding sites and allosteric regulation of enzymes, or implemented in a drug discovery process to search for potential molecular targets and novel selective inhibitors/effectors. The server, documentation and examples are freely available at http://biokinet.belozersky.msu.ru/pocketzebra and there are no login requirements. PMID:24852248

Suplatov, Dmitry; Kirilin, Eugeny; Arbatsky, Mikhail; Takhaveev, Vakil; Švedas, Vytas

2014-01-01

217

Prevalencia de Staphylococcus aureus, Vibrio spp. y enterobacterias en carne de pepitona, Arca zebra, comercializada en Cumaná, Venezuela / Prevalence of Staphylococcus aureus, Vibrio spp., and enterobacteria in pepitona, Arca zebra, commercialized in Cumaná, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish La pepitona, Arca zebra, (Mollusca: Bivalvia: Arcidae) es un producto de consumo masivo en el oriente de Venezuela. Se recolectaron mensualmente (marzo a septiembre 2004), muestras de pepitonas provenientes de expendios del Mercado Municipal de Cumaná, con el fin de determinar su condición higiénico [...] -sanitaria. Se efectuaron recuentos en placa de Staphylococcus aureus, enterobacterias y detección de Vibrio spp. La identificación se realizó utilizando pruebas bioquímicas diferenciales basadas en la actividad metabólica de cada cepa aislada. Los análisis revelaron contaminación por S. aureus y enterobacterias en las muestras de carne de pepitonas, con valores promedio de 1,8 x 10² a 6,4 x 10³ y 2,5 x 10² a 5,4 x 10³ UFC/g, respectivamente. Se aislaron 61 cepas de S. aureus, de las cuales 37,7% resultaron ser positivas a la prueba de coagulasa y 42,6% a la DNAsa. Se identificaron diez especies pertenecientes a la familia Enterobacteriaceae, siendo la predominante Escherichia coli con 25% de prevalencia. También fueron identificadas las siguientes especies de Vibrio: V. alginolyticus, V. parahaemolyticus, V. metchinikovii, V. fluvialis y V. mimicus. Se demostró la presencia de patógenos en carne de pepitona libremente expendida en el Mercado Municipal de Cumaná. Abstract in english Pepitona or turkey wing, Arca zebra (Mollusca: Bivalvia: Arcidae), is a product of massive consumption in eastern Venezuela. Monthly samples (march to september 2004) of pepitona meat were taken from vending places in the Cumana Municipal Market, in order to determine their hygienic conditions. Plat [...] e cultures of Staphylococcus aureus and enterobacteriae, and detection of Vibrio spp. were made. The identification was made using differential biochemical tests based upon the metabolic activity of each isolated strain. The analyses showed a high degree of contamination by S. aureus and enterobacteria in samples of pepitona meat, with average values 1.8 x 10² to 6.4 x 10³, and 2.5 x 10² to 5.4 x 10³ CFU/g, respectively. A total number of 61 strains of S. aureus were isolated, of which 39.1% yielded positive to the coagulase test and 41.7% to the DNAse test. Ten species of the family Enterobacteriaceae were identified, being Escherichia coli the most predominant with 25% prevalence. The following Vibrio species were identified: V. alginolyticus, V. parahaemolyticus, V. metchinikovii, V. fluvialis and V. mimicus. The presence of pathogens in pepitona meat freely sold to the public in the Municipal Market of Cumaná was demonstrated.

Daniel, Muñoz; Crucita, Graü de Marín; Carlos, Martínez; Hilda, Marval; Aracelis, Zerpa.

218

Contribución al conocimiento de los macromoluscos bentónicos asociados a la pepitona, Arca zebra (Swainson, 1833), del banco natural de Chacopata, Península de Araya, Venezuela / Contribution to the knowledge of benthonic macromollusks associated to pepitona, Arca zebra (Swainson, 1833), in the natural bank of Chacopata, Araya Peninsula, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Como parte de un programa de monitoreo de áreas marinas del norte del estado Sucre, Venezuela, se analizó la diversidad malacológica de los macromoluscos asociados a la pepitona, Arca zebra, ubicado en el banco natural de Chacopata, desde enero hasta marzo 2006. Se identificaron un total de 31 espec [...] ies pertenecientes a 21 familias y 4 clases de moluscos, que incluyeron 12 especies de bivalvos, 17 gasterópodos, un cefalópodo y un poliplacóforo. Los parámetros de diversidad numérica fueron bajos (H’ = 1,907 a 2,034 bits/ind; J’ = 0,591 a 0,649, IS = 0,209 a 0,258) mientras que la dominancia osciló entre 35,9 y 46,4%. El índice ? de la serie logarítmica mensual fluctúo entre 4,819 y 6,917. La escasa variación mensual de la diversidad confirma investigaciones previas e indican que la estructura comunitaria es estable. Se determinaron 19 especies constantes siendo las mas abundantes los bivalvos Arca zebra, Chama congregata, Chama sarda y Chama sarda, mientras que en los gasterópodos fueron Chicoreus brevifrons y Crepidula ausitulata. Arca zebra fue la especie dominante en numero, indicando que desempeña el papel más importante en la comunidad como un eficiente filtrador, lo cual le permite soportar una de las pesquerías más importantes de la región. Abstract in english As part of a monitoring program of the marine areas at northern of Sucre state, Venezuela, we examined the malacological diversity of macromollusk associated to ark shell, Arca zebra, located in the natural bank of Chacopata. Monthly sampling was made from January to March 2006. A total of 31 specie [...] s were identified belonging to 21 families of 4 classes of mollusk that included 12 species of bivalves, 17 gastropods, one cephalopods and one poliplacophoro. Parameters of numeric diversity were low (H’ = 1.907 to 2.034 bits/ind; J’= 0.591 to 0.649; IS = 0.209 to 0.258), while the dominance oscillated between 35.99 and 43.61%. Alpha index of the logarithmic series model fluctuated between 4.819 and 6.917. The scarce monthly variation confirms previous research and they indicate that the community structure is stable. Fourteen constant species were determined being those more abundant the bivalves Arca zebra, Chama congregate y Chama sarda, while the gastropods were Chicoreus brevifrons and Crepidula ausitulata. Arca zebra was the dominant species in number and occupied a central role in the community, supporting one of the most important fisheries in the area.

Licet, Berenice; Acosta, Vanesa; Prieto, Antulio; Garcia, Natividad.

2009-03-01

219

Encoding of naturalistic optic flow by motion sensitive neurons of nucleus rotundus in the zebra finch (Taeniopygia guttata.  

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Full Text Available The retinal image changes that occur during locomotion, the optic flow, carry information about self-motion and the three-dimensional structure of the environment. Especially fast moving animals with only little binocular vision depend on these depth cues for manoeuvring. They actively control their gaze to facilitate perception of depth based on cues in the optic flow. In the visual system of birds, nucleus rotundus neurons were originally found to respond to object motion but not to background motion. However, when background and object were both moving, responses increase the more the direction and velocity of object and background motion on the retina differed. These properties may play a role in representing depth cues in the optic flow. We therefore investigated how neurons in nucleus rotundus respond to optic flow that contains depth cues. We presented simplified and naturalistic optic flow on a panoramic LED display while recording from single neurons in nucleus rotundus of anaesthetized zebra finches. Unlike most studies on motion vision in birds, our stimuli included depth information. We found extensive responses of motion selective neurons in nucleus rotundus to optic flow stimuli. Simplified stimuli revealed preferences for optic flow reflecting translational or rotational self-motion. Naturalistic optic flow stimuli elicited complex response modulations, but the presence of objects was signalled by only few neurons. The neurons that did respond to objects in the optic flow, however, show interesting properties.

DennisEckmeier

2013-09-01

220

Arrhythmic Song Exposure Increases ZENK Expression in Auditory Cortical Areas and Nucleus Taeniae of the Adult Zebra Finch  

Science.gov (United States)

Rhythm is important in the production of motor sequences such as speech and song. Deficits in rhythm processing have been implicated in human disorders that affect speech and language processing, including stuttering, autism, and dyslexia. Songbirds provide a tractable model for studying the neural underpinnings of rhythm processing due to parallels with humans in neural structures and vocal learning patterns. In this study, adult zebra finches were exposed to naturally rhythmic conspecific song or arrhythmic song. Immunohistochemistry for the immediate early gene ZENK was used to detect neural activation in response to these two types of stimuli. ZENK was increased in response to arrhythmic song in the auditory association cortex homologs, caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM), and the avian amygdala, nucleus taeniae (Tn). CMM also had greater ZENK labeling in females than males. The increased neural activity in NCM and CMM during perception of arrhythmic stimuli parallels increased activity in the human auditory cortex following exposure to unexpected, or perturbed, auditory stimuli. These auditory areas may be detecting errors in arrhythmic song when comparing it to a stored template of how conspecific song is expected to sound. CMM may also be important for females in evaluating songs of potential mates. In the context of other research in songbirds, we suggest that the increased activity in Tn may be related to the value of song for assessing mate choice and bonding or it may be related to perception of arrhythmic song as aversive. PMID:25259620

Lampen, Jennifer; Jones, Katherine; McAuley, J. Devin; Chang, Soo-Eun; Wade, Juli

2014-01-01

 
 
 
 
221

Systemic Amyloidosis and Testicular Interstitial Tumor in a Zebra Finch (Taeniopygia guttata: a Case Report in Iran  

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Full Text Available Abstract Systemic amyloidosis and testicular interstitial tumor are rare conditions in birds and this is the first report in Iran. A male zebra finch was presented because of white diarrhea, anorexia, loss of weight and lethargy. At necropsy, the small intestine was edematous and congested. The spleen appeared pale. The liver was large, firm and brown. One testis was cystic and neoplastic and the remaining testis was atrophic. Histologically, amyloid materials were seen predominantly in the liver and spleen. Hyaline substances were deposited in the Disse space and in the media of blood vessels of the liver. In spleen, marked deposits thickened the basement membranes of blood vessels and extended into the surrounding parenchyma. In addition, there were lesser degrees of amyloidosis in other organs such as small intestine. Amyloid stained positively with Congo red. In testis, there was encapsulated unilateral interstitial cell tumor, with multiple foci of necrosis and hemorrhage. The neoplastic cells were round to polyhedral, with small round hyperchromatic nuclei and finely vacuolated cytoplasm. Signs of feminization were observed. The cause of amyloidosis in this study was not conclusively identified.

Mehrnoush Moeini Jazani

2011-09-01

222

17beta-Estradiol levels in male zebra finch brain: combining Palkovits punch and an ultrasensitive radioimmunoassay.  

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Local aromatization of testosterone into 17beta-estradiol (E(2)) is often required for the physiological and behavioral actions of testosterone. In most vertebrates, aromatase is expressed in a few discrete brain regions. While many studies have measured brain aromatase mRNA or activity, very few studies have measured brain E(2) levels, particularly in discrete brain regions, because of technical challenges. Here, we used the Palkovits punch technique to isolate 13 discrete brain nuclei from adult male zebra finches. Steroids were extracted via solid phase extraction. E(2) was then measured with an ultrasensitive, specific and precise radioimmunoassay. Our protocol leads to high recovery of E(2) (84%) and effectively removes interfering brain lipids. E(2) levels were high in aromatase-rich regions such as caudal medial nidopallium and hippocampus. E(2) levels were intermediate in the medial preoptic area, ventromedial nucleus of the hypothalamus, lateral and medial magnocellular nuclei of anterior nidopallium, nucleus taeniae of the amygdala, and Area X. E(2) levels were largely non-detectable in the cerebellum, HVC, lateral nidopallium and optic lobes. Importantly, E(2) levels were significantly lower in plasma than in the caudal medial nidopallium. This protocol allows one to measure E(2) in discrete brain regions and potentially relate local E(2) concentrations to aromatase activity and behavior. PMID:20144613

Charlier, Thierry D; Po, Kelvin W L; Newman, Amy E M; Shah, Amit H; Saldanha, Colin J; Soma, Kiran K

2010-05-15

223

Differential maternal testosterone allocation among siblings benefits both mother and offspring in the zebra finch Taeniopygia guttata.  

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Parents are selected to preferentially invest in the offspring with highest reproductive value. One mechanism for achieving this is the modification of competitive asymmetries between siblings by maternal hormones. In many organisms, offspring value varies according to birth position in the brood, which determines survival chances and competitive advantage over access to resources. In birds, variation in yolk androgen allocation over the laying sequence is thought to modulate dominance of senior chicks over junior brood mates. We tested this hypothesis in zebra finches, which show a naturally decreasing pattern of within-clutch testosterone allocation. We abolished these within-clutch differences by experimentally elevating yolk testosterone levels in eggs 2-6 to the level of egg 1, and we assessed fitness measures for junior offspring (eggs 2-6), senior offspring (egg 1), and their mothers. Testosterone-injected eggs hatched later than control eggs. Junior, but not senior, chicks in testosterone-treated broods attained poorer phenotypic quality compared to control broods, which was not compensated for by positive effects on seniors. Mothers were generally unaffected by clutch treatment. Thus, naturally decreasing within-clutch yolk testosterone allocation appears to benefit all family members and does not generally enhance brood reduction by favoring senior chicks, in contrast to the widely held assumption. PMID:21670578

Boncoraglio, Giuseppe; Groothuis, Ton G G; von Engelhardt, Nikolaus

2011-07-01

224

Comet and micronucleus assays in zebra mussel cells for genotoxicity assessment of surface drinking water treated with three different disinfectants.  

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The aim of this research was to study the influence of classic (sodium hypochlorite and chlorine dioxide) and alternative (peracetic acid [PAA]) disinfectants on the formation of mutagens in surface waters used for human consumption. For this proposal, in vivo genotoxicity tests (Comet and micronucleus assay) were performed in an experimental pilot plant set up near Lake Trasimeno (Central Italy). The effects were detected in different tissues (haemocytes for the Comet assay and gills for the micronucleus test [MN]) of Dreissena polymorpha exposed in experimental basins supplied with lake water with/without the different disinfectants. Specimen collection was performed before disinfectant input for both tests and after the start of disinfection (3 h and 20 days for the Comet assay and 10 and 20 days for micronucleus test, respectively) to assess short- and long- term exposure effects during three sampling campaigns (October 2000, February 2001, and June 2001). Seasonal differences in baseline levels of DNA migration and micronucleus frequency were observed. Raw water quality modulation on disinfection by-product formation was shown. The results of the micronucleus and Comet assays on zebra mussel cells after in situ exposure to water disinfected with the two chlorinated compounds clearly indicate DNA/by-product interaction. PAA did not induce either clastogenic/aneugenic effects or DNA damage on this bioindicator. PMID:15364524

Bolognesi, Claudia; Buschini, Annamaria; Branchi, Elisa; Carboni, Pamela; Furlini, Mariangela; Martino, Anna; Monteverde, Martino; Poli, Paola; Rossi, Carlo

2004-10-15

225

The presence of an audience modulates responses to familiar call stimuli in the male zebra finch forebrain.  

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The ability to recognize familiar individuals is crucial for establishing social relationships. The zebra finch, a highly social songbird species that forms lifelong pair bonds, uses a vocalization, the distance call, to identify its mate. However, in males, this ability depends on social conditions, requiring the presence of an audience. To evaluate whether the presence of bystanders modulates the auditory processing underlying recognition abilities, we assessed, by using a lightweight telemetry system, whether electrophysiological responses driven by familiar and unfamiliar female calls in a high-level auditory area [the caudomedial nidopallium (NCM)] were modulated by the presence of conspecific males. Males had experienced the call of their mate for several months and the call of a familiar female for several days. When they were exposed to female calls in the presence of two male conspecifics, NCM neurons showed greater responses to the playback of familiar female calls, including the mate's call, than to unfamiliar ones. In contrast, no such discrimination was observed in males when they were alone or when call-evoked responses were collected under anaesthesia. Together, these results suggest that NCM neuronal activity is profoundly influenced by social conditions, providing new evidence that the properties of NCM neurons are not simply determined by the acoustic structure of auditory stimuli. They also show that neurons in the NCM form part of a network that can be shaped by experience and that probably plays an important role in the emergence of communication sound recognition. PMID:25145963

Menardy, F; Giret, N; Del Negro, C

2014-11-01

226

Integrated use of biomarkers and bioaccumulation data in Zebra mussel (Dreissena polymorpha) for site-specific quality assessment.  

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One of the useful biological tools for environmental management is the measurement of biomarkers whose changes are related to the exposure to chemicals or environmental stress. Since these responses might vary with different contaminants or depending on the pollutant concentration reached in the organism, the support of bioaccumulation data is needed to prevent false conclusions. In this study, several persistent organic pollutants -- 23 polychlorinated biphenyl (PCB) congeners, 11 polycyclic aromatic hydrocarbons (PAHs), six dichlorodiphenyltricholroethane (DDT) relatives, hexachlorobenzene (HCB), chlorpyrifos and its oxidized metabolite -- and some herbicides (lindane and the isomers alpha, beta, delta; terbutilazine; alachlor; metolachlor) were measured in the soft tissues of the freshwater mollusc Zebra mussel (Dreissena polymorpha) from 25 sampling sites in the Italian portions of the sub-alpine great lakes along with the measure of ethoxyresorufin dealkylation (EROD) and acetylcholinesterase (AChE) activity. The linkage between bioaccumulation and biomarker data allowed us to create site-specific environmental quality indexes towards man-made chemicals. This classification highlighted three different degrees of xenobiotic contamination of the Italian sub-alpine great lakes: a high water quality in Lake Lugano with negligible pollutant levels and no effects on enzyme activities, an homogeneous poor quality for Lakes Garda, Iseo and Como, and the presence of some xenobiotic point-sources in Lake Maggiore, whose ecological status could be jeopardized, also due to the heavy DDT contamination revealed since 1996. PMID:16966160

Binelli, A; Ricciardi, F; Riva, C; Provini, A

2006-01-01

227

The influence of temperature, daylength and sucrose concentration on the growth and development of Alstroemeria 'Zebra' in vitro  

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Full Text Available The influence of temperature, daylength and sucrose concentration on the growth and development of Alstroemeria 'Zebra' in vitro was investigated. Only slightly more lateral rhizomes were formed at 25°C in comparison with 17°C on the medium with BA. Presence of BA in the medium strongly increased number of upright growing shoots and more shoots were formed in temperature 25°C than in temperature 17°C. Rhizome multiplication and formation of upright growing shoots were not significantly influenced by daylength. Sucrose was required for the formation of lateral rhizomes, upright growing shoots and roots. The highest number Of lateral rhizomes was observed on the medium containing 60 and 80 gl-1 sucrose and BA. Presence of BA in the medium with different sucrose concentrations markedly influenced the formation of upright growing shoots; the highest number of shoots was found on the explants cultured on the media with 20 and 30 gl-1 sucrose. Low and high concentrations of sucrose inhibited upright growing shoots formation and their elongation. Rhizogenesis was not observed on rhizomes growing on the medium without sucrose and with 10 gl-1 sucrose, either in the presence or absence of NAA„ The number of roots per plantlet on the medium with NAA increased with increasing sucrose levels. The highest sucrose concentrations slightly inhibited roots formation.

Eleonora Gabryszewska

1996-12-01

228

Mercury levels and trends (1993-2009) in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) from German surface waters.  

Science.gov (United States)

Mercury concentrations have been analysed in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) collected at 17 freshwater sites in Germany from 1993-2009 and 1994-2009, respectively, within the German Environmental Specimen programme. Mercury concentrations in bream ranged from 21 to 881 ng g(-1) wet weight with lowest concentrations found at the reference site Lake Belau and highest in fish from the river Elbe and its tributaries. Statistical analysis revealed site-specific differences and significant decreasing temporal trends in mercury concentrations at most of the sampling sites. The decrease in mercury levels in bream was most pronounced in fish from the river Elbe and its tributary Mulde, while in fish from the river Saale mercury levels increased. Temporal trends seem to level off in recent years. Mercury concentrations in zebra mussels were much lower than those in bream according to their lower trophic position and varied by one order of magnitude from 4.1 to 42 ng g(-1) wet weight (33-336 ng g(-1) dry weight). For zebra mussels, trend analyses were performed for seven sampling sites at the rivers Saar and Elbe of which three showed significant downward trends. There was a significant correlation of the geometric mean concentrations in bream and zebra mussel over the entire study period at each sampling site (Pearson's correlation coefficient=0.892, p=0.00002). A comparison of the concentrations in bream with the environmental quality standard (EQS) of 20 ng g(-1) wet weight set for mercury in biota by the EU showed that not a single result was in compliance with this limit value, not even those from the reference site. Current mercury levels in bream from German rivers exceed the EQS by a factor 4.5-20. Thus, piscivorous top predators are still at risk of secondary poisoning by mercury exposure via the food chain. It was suggested focusing monitoring of mercury in forage fish (trophic level 3 or 4) for compliance checking with the EQS for biota and considering the age dependency of mercury concentrations in fish in the monitoring strategy. PMID:22071369

Lepom, Peter; Irmer, Ulrich; Wellmitz, Jörg

2012-01-01

229

The songbird syrinx morphome: a three-dimensional, high-resolution, interactive morphological map of the zebra finch vocal organ  

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Full Text Available Abstract Background Like human infants, songbirds learn their species-specific vocalizations through imitation learning. The birdsong system has emerged as a widely used experimental animal model for understanding the underlying neural mechanisms responsible for vocal production learning. However, how neural impulses are translated into the precise motor behavior of the complex vocal organ (syrinx to create song is poorly understood. First and foremost, we lack a detailed understanding of syringeal morphology. Results To fill this gap we combined non-invasive (high-field magnetic resonance imaging and micro-computed tomography and invasive techniques (histology and micro-dissection to construct the annotated high-resolution three-dimensional dataset, or morphome, of the zebra finch (Taeniopygia guttata syrinx. We identified and annotated syringeal cartilage, bone and musculature in situ in unprecedented detail. We provide interactive three-dimensional models that greatly improve the communication of complex morphological data and our understanding of syringeal function in general. Conclusions Our results show that the syringeal skeleton is optimized for low weight driven by physiological constraints on song production. The present refinement of muscle organization and identity elucidates how apposed muscles actuate different syringeal elements. Our dataset allows for more precise predictions about muscle co-activation and synergies and has important implications for muscle activity and stimulation experiments. We also demonstrate how the syrinx can be stabilized during song to reduce mechanical noise and, as such, enhance repetitive execution of stereotypic motor patterns. In addition, we identify a cartilaginous structure suited to play a crucial role in the uncoupling of sound frequency and amplitude control, which permits a novel explanation of the evolutionary success of songbirds.

Düring Daniel N

2013-01-01

230

The songbird syrinx morphome: a three-dimensional, high-resolution, interactive morphological map of the zebra finch vocal organ  

DEFF Research Database (Denmark)

Background: Like human infants, songbirds learn their species-specific vocalizations through imitation learning. The birdsong system has emerged as a widely used experimental animal model for understanding the underlying neural mechanisms responsible for vocal production learning. However, how neural impulses are translated into the precise motor behavior of the complex vocal organ (syrinx) to create song is poorly understood. First and foremost, we lack a detailed understanding of syringeal morphology. Results: To fill this gap we combined non-invasive (high-field magnetic resonance imaging and micro-computed tomography) and invasive techniques (histology and micro-dissection) to construct the annotated high-resolution three-dimensional dataset, or morphome, of the zebra finch (Taeniopygia guttata) syrinx. We identified and annotated syringeal cartilage, bone and musculature in situ in unprecedented detail. We provide interactive three-dimensional models that greatly improve the communication of complex morphological data and our understanding of syringeal function in general. Conclusions: Our results show that the syringeal skeleton is optimized for low weight driven by physiological constraints on song production. The present refinement of muscle organization and identity elucidates how apposed muscles actuate different syringeal elements. Our dataset allows for more precise predictions about muscle co-activation and synergies and has important implications for muscle activity and stimulation experiments. We also demonstrate how the syrinx can be stabilized during song to reduce mechanical noise and, as such, enhance repetitive execution of stereotypic motor patterns. In addition, we identify a cartilaginous structure suited to play a crucial role in the uncoupling of sound frequency and amplitude control, which permits a novel explanation of the evolutionary success of songbirds.

During, D. N.; Ziegler, A.

2013-01-01

231

Sexual differentiation of brain and behavior in quail and zebra finches: studies with a new aromatase inhibitor, R76713.  

Science.gov (United States)

In many species of vertebrates, major sex differences affect reproductive behavior and endocrinology. Most of these differences do not result from a direct genomic action but develop following early exposure to a sexually differentiated endocrine milieu. In rodents, the female reproductive phenotype mostly develops in the absence of early steroid influence and male differentiation is imposed by the early action of testosterone, acting at least in part through its central conversion into estrogens or aromatization. This pattern of differentiation does not seem to be applicable to avian species. In Japanese quail (Coturnix japonica), injection of estrogens into male embryos causes a permanent loss of the capacity to display male-type copulatory behavior when exposed to testosterone in adulthood. Based on this experimental result, it was proposed that the male reproductive phenotype is "neutral" in birds (i.e. develops in the absence of endocrine influence) and that endogenous estradiol secreted by the ovary of the female embryo is responsible for the physiological demasculinization of females. This model could be recently confirmed. Females indeed display a higher level of circulating estrogens that males during the second part of their embyronic life. In addition, treatment of female embryos with the potent aromatase inhibitor, R76713 or racemic vorozole which suppresses the endogenous secretion of estrogens maintains in females the capacity to display the full range of male copulatory behaviors. The brain mechanisms that control this sexually differentiated behavior have not been identified so far but recent data suggest that they should primarily concern a sub-population of aromatase-immunoreactive neurons located in the lateral parts of the sexually dimorphic preoptic nucleus. The zebra finch (Taeniopygia guttata) exhibits a more complex, still partly unexplained, differentiation pattern. In this species, early treatment with exogenous estrogens produces a masculinization of singing behavior in females and a demasculinization of copulatory behavior in males.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7626466

Foidart, A; Balthazart, J

1995-06-01

232

Use of transplanted Zebra mussels (Dreissena polymorpha) to assess the bioavailability of microcontaminants in Flemish surface waters.  

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Zebra mussels (Dreissena polymorpha) were translocated in cages to 56 water bodies in Flanders (Belgium) during summer 2001. After six weeks, concentrations of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), p,p'-DDE, and trace metals were measured in the transplanted mussels. It was investigated whether total dissolved water and sediment pollutant levels or bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) were predictive for mussel tissue levels. The sample sites covered a broad range both in terms of the type and concentration of the pollutants, and this was reflected in large differences in tissue concentrations of all pollutants among the sites. The highest pollutant levels in mussels were among the highest reported in the literature. For Cd and Zn levels up to 33 and 1994 microg/g dry wt. respectively were found. The lowest levels were comparable to those from uncontaminated sites in Europe and the U.S. For Cd and Zn respectively 51 and 75% of the variation in tissue levels was described. For both metals, dissolved and particulate metal contributed to the variation in accumulation. For other pollutants, relationships between tissue concentration and water or sediment concentration were weak or nonsignificant. Then the measured environmental factors (dissolved calcium, pH, oxygen, organic carbon and clay content in the sediment) were taken into account applying multiple regression analysis, and no increase in the described variation of pollutant accumulation was observed. The BAF and BSAF for all pollutants varied up to 1000-fold even after TOC-normalization. Clear negative relationships were found between BAFs/ BSAFs and environmental levels. However, even at constant environmental concentrations a 10- to 100-fold variation in BAFs/BSAFs was observed. This study illustrated the need for biological monitoring since neither environmental PMID:15819201

Bervoets, Lieven; Voets, Judith; Covaci, Adrian; Chu, Shaogang; Qadah, Diab; Smolders, Roel; Schepens, Paul; Blust, Ronny

2005-03-15

233

Sex-specific activity and function of hypothalamic nonapeptide neurons during nest-building in zebra finches.  

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Vertebrate species from fish to humans engage in a complex set of preparatory behaviors referred to as nesting; yet despite its phylogenetic ubiquity, the physiological and neural mechanisms that underlie nesting are not well known. We here test the hypothesis that nesting behavior is influenced by the vasopressin-oxytocin (VP-OT) peptides, based upon the roles they play in parental behavior in mammals. We quantified nesting behavior in male and female zebra finches following both peripheral and central administrations of OT and V1a receptor (OTR and V1aR, respectively) antagonists. Peripheral injections of the OTR antagonist profoundly reduce nesting behavior in females, but not males, whereas comparable injections of V1aR antagonist produce relatively modest effects in both sexes. However, central antagonist infusions produce no effects on nesting, and OTR antagonist injections into the breast produce significantly weaker effects than those into the inguinal area, suggesting that antagonist effects are mediated peripherally, likely via the oviduct. Finally, immunocytochemistry was used to quantify nesting-induced Fos activation of nonapeptide neurons in the paraventricular and supraoptic nuclei of the hypothalamus and the medial bed nucleus of the stria terminalis. Nest-building induced Fos expression within paraventricular VP neurons of females but not males. Because the avian forms of OT (Ile(8)-OT; mesotocin) and VP (Ile(3)-VP; vasotocin) exhibit high affinity for the avian OTR, and because both peptide forms modulate uterine contractility, we hypothesize that nesting-related stimuli induce peptide release from paraventricular vasotocin neurons, which then promote female nesting via peripheral feedback from OTR binding in the oviduct uterus. PMID:24126135

Klatt, James D; Goodson, James L

2013-11-01

234

Characterization of uranium effects on the zebra fish Danio rerio. Stress mechanisms, neuro-toxicity and mitochondrial metabolism  

International Nuclear Information System (INIS)

This research explored several biological effects of uranium (U) in zebra fish exposed to low waterborne uranium concentrations (20 and 100 microgram/L). In tissue specific study (brain, liver, skeletal muscles and gills) of transcriptional responses in 20 genes identified the nature of the potential U effects during 28 days of exposure followed by an 8-day depuration phase in connection with U bioaccumulation. Liver and gills accumulate high concentrations of U and the depuration is efficient contrary to the brain and muscles. U exposure induced a later response in liver (inflammatory process, apoptosis and detoxification) and gills (oxidative balance) and an early one in brain (neuronal response) and muscles (mitochondrial metabolism). Brain and muscles appear sensitive since defence mechanisms are inefficient above low concentrations. A further study on these two organs examined the function and protein content of the respiratory mitochondrial chain following U exposure. An inhibition of the respiratory control ratio for the lowest concentration, variation in the protein synthesis of the complex IV (induction of cytochrome c oxidase sub-unit I and IV) and histological damage (dilatation in brain and vacuolisation in muscles) were observed. Another study focused on the early effects on the brain and was accomplished through a large transcriptional analysis coupled with examinations of the olfactory bulb ultrastructure. A depression of genes encoding olfactory receptor or111-7 and or102-5 was observed as rapidly as 3 days post-exposure to the lowest concentration of U. These responses and histological injuries suggest that the olfactory system could be sensitive to U exposure. (author)

235

Sexually Dimorphic and Developmentally Regulated Expression of Tubulin Specific Chaperone Protein A in the LMAN of Zebra Finches  

Science.gov (United States)

Sex differences in brain and behavior exist across vertebrates, but the molecular factors regulating their development are largely unknown. Songbirds exhibit substantial sexual dimorphisms. In zebra finches, only males sing, and the brain areas regulating song learning and production are much larger in males. Recent data suggest that sex chromosome genes (males ZZ; females ZW) may play roles in sexual differentiation. The present studies tested the hypothesis that a Z-gene, tubulin specific chaperone protein A (TBCA), contributes to sexual differentiation of the song system. This taxonomically conserved gene is integral to microtubule synthesis, and within the song system, its mRNA is specifically increased in males compared to females in the lateral magnocellular nucleus of the anterior nidopallium (LMAN), a region critical for song learning and plasticity. Using in situ hybridization, Western blot analysis, and immunohistochemistry, we observed effects of both age and sex on TBCA mRNA and protein expression. The transcript is increased in males compared to females at three juvenile ages, but not in adults. TBCA protein, both the number of immunoreactive cells and relative concentration in LMAN, is diminished in adults compared to juveniles. The latter was also increased in males compared to females at post-hatching day 25. With double-label immunofluorescence and retrograde tract tracing, we also document that the majority of TBCA+ cells in LMAN are neurons, and that they include RA-projecting cells. These results indicate that TBCA is both temporally and spatially primed to facilitate the development of a sexually dimorphic neural pathway critical for song. PMID:23727504

Qi, Linda M.; Wade, Juli

2013-01-01

236

Sexually dimorphic and developmentally regulated expression of tubulin-specific chaperone protein A in the LMAN of zebra finches.  

Science.gov (United States)

Sex differences in brain and behavior exist across vertebrates, but the molecular factors regulating their development are largely unknown. Songbirds exhibit substantial sexual dimorphisms. In zebra finches, only males sing, and the brain areas regulating song learning and production are much larger in males. Recent data suggest that sex chromosome genes (males ZZ; females ZW) may play roles in sexual differentiation. The present studies tested the hypothesis that a Z-gene, tubulin-specific chaperone protein A (TBCA), contributes to sexual differentiation of the song system. This taxonomically conserved gene is integral to microtubule synthesis, and within the song system, its mRNA is specifically increased in males compared to females in the lateral magnocellular nucleus of the anterior nidopallium (LMAN), a region critical for song learning and plasticity. Using in situ hybridization, Western blot analysis, and immunohistochemistry, we observed effects of both age and sex on TBCA mRNA and protein expression. The transcript is increased in males compared to females at three juvenile ages, but not in adults. TBCA protein, both the number of immunoreactive cells and relative concentration in LMAN, is diminished in adults compared to juveniles. The latter was also increased in males compared to females at post-hatching day 25. With double-label immunofluorescence and retrograde tract tracing, we also document that the majority of TBCA+ cells in LMAN are neurons, and that they include robust nucleus of the arcopallium-projecting cells. These results indicate that TBCA is both temporally and spatially primed to facilitate the development of a sexually dimorphic neural pathway critical for song. PMID:23727504

Qi, L M; Wade, J

2013-09-01

237

Functional magnetic resonance imaging in zebra finch discerns the neural substrate involved in segregation of conspecific song from background noise.  

Science.gov (United States)

Recently, fMRI was introduced in a well-documented animal model for vocal learning, the songbird. Using fMRI and conspecific signals mixed with different levels of broadband noise, we now demonstrate auditory-induced activation representing discriminatory properties of auditory forebrain regions in anesthetized male zebra finches (Taeniopygia guttata). Earlier behavioral tests showed comparable calling responses to the original conspecific song stimulus heard outside and inside the magnet. A significant fMRI response was elicited by conspecific song in the primary auditory thalamo-recipient subfield L2a; in neighboring subareas L2b, L3, and L; and in the rostral part of the higher-order auditory area NCM (caudomedial nidopallium). Temporal BOLD response clustering revealed rostral and caudal clusters that we defined as "cluster Field L" and "cluster NCM", respectively. However, because the actual border between caudal Field L subregions and NCM cannot be seen in the structural MR image and is not precisely reported elsewhere, the cluster NCM might also contain subregion L and the medial extremes of the subregions L2b and L3. Our results show that whereas in cluster Field L the response was not reduced by added noise, in cluster NCM the response was reduced and finally disappeared with increasing levels of noise added to the song stimulus. The activation in cluster NCM was significant for only two experimental stimuli that showed significantly more behavioral responses than the more degraded stimuli, suggesting that the first area within the auditory system where the ability to discern song from masking noise emerges is located in cluster NCM. PMID:17881485

Boumans, Tiny; Vignal, Clémentine; Smolders, Alain; Sijbers, Jan; Verhoye, Marleen; Van Audekerke, Johan; Mathevon, Nicolas; Van der Linden, Annemie

2008-02-01

238

Current state-of-the-art of auditory functional MRI (fMRI) on zebra finches: technique and scientific achievements.  

Science.gov (United States)

Songbirds provide an excellent model system exhibiting vocal learning associated with an extreme brain plasticity linked to quantifiable behavioral changes. This animal model has thus far been intensively studied using electrophysiological, histological and molecular mapping techniques. However, these approaches do not provide a global view of the brain and/or do not allow repeated measures, which are necessary to establish correlations between alterations in neural substrate and behavior. In contrast, functional Magnetic Resonance Imaging (fMRI) is a non-invasive in vivo technique which allows one (i) to study brain function in the same subject over time, and (ii) to address the entire brain at once. During the last decades, fMRI has become one of the most popular neuroimaging techniques in cognitive neuroscience for the study of brain activity during various tasks ranging from simple sensory-motor to highly cognitive tasks. By alternating various stimulation periods with resting periods during scanning, resting and task-specific regional brain activity can be determined with this technique. Despite its obvious benefits, fMRI has, until now, only been sparsely used to study cognition in non-human species such as songbirds. The Bio-Imaging Lab (University of Antwerp, Belgium) was the first to implement Blood Oxygen Level Dependent (BOLD) fMRI in songbirds - and in particular zebra finches - for the visualization of sound perception and processing in auditory and song control brain regions. The present article provides an overview of the establishment and optimization of this technique in our laboratory and of the resulting scientific findings. The introduction of fMRI in songbirds has opened new research avenues that permit experimental analysis of complex sensorimotor and cognitive processes underlying vocal communication in this animal model. PMID:22960664

Van Ruijssevelt, Lisbeth; Van der Kant, Anne; De Groof, Geert; Van der Linden, Annemie

2013-06-01

239

Learning to cope with degraded sounds: female zebra finches can improve their expertise in discriminating between male voices at long distances.  

Science.gov (United States)

Reliable transmission of acoustic information about individual identity is of critical importance for pair bond maintenance in numerous monogamous songbirds. However, information transfer can be impaired by environmental constraints such as external noise or propagation-induced degradation. Birds have been shown to use several adaptive strategies to deal with difficult signal transmission contexts. Specifically, a number of studies have suggested that vocal plasticity at the emitter's level allows birds to counteract the deleterious effects of sound degradation. Although the communication process involves both the emitter and the receiver, perceptual plasticity at the receiver's level has received little attention. Here, we explored the reliability of individual recognition by female zebra finches (Taeniopygia guttata), testing whether perceptual training can improve discrimination of degraded individual vocal signatures. We found that female zebra finches are proficient in discriminating between calls of individual males at long distances, and even more so when they can train themselves with increasingly degraded signals over time. In this latter context, females succeed in discriminating between males as far as 250 m. This result emphasizes that adaptation to adverse communication conditions may involve not only the emitter's vocal plasticity but also the receptor's decoding process through on-going learning. PMID:24948627

Mouterde, Solveig C; Elie, Julie E; Theunissen, Frédéric E; Mathevon, Nicolas

2014-09-01

240

Environmental concentrations of 3,4-methylenedioxymethamphetamine (MDMA)-induced cellular stress and modulated antioxidant enzyme activity in the zebra mussel.  

Science.gov (United States)

Recent monitoring studies showed measurable levels of the 3,4-methylenedioxymethamphetamine (MDMA) in aquatic environments. However, no information is currently available on its potential hazard to aquatic non-target organisms. The aim of this study was to investigate the potential sub-lethal effects induced by 14-day exposures to low MDMA concentrations (0.05 and 0.5 ?g/L) to zebra mussel (Dreissena polymorpha) specimens through the application of a biomarker suite. The trypan blue exclusion method and the neutral red retention assay (NRRA) were used to assess MDMA cytotoxicity. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST), as well as the lipid peroxidation (LPO) and protein carbonyl content (PCC), were measured as oxidative stress indexes. The single cell gel electrophoresis (SCGE) assay, the DNA diffusion assay, and the micronucleus test (MN test) were applied to investigate DNA damage, while filtration rate was measured as physiological parameter. Despite significant decrease in lysosome membrane stability, hemocyte viability and imbalances in CAT and GST activities pointed out at the end of the exposure to 0.5 ?g/L, no significant variations for the other end points were noticed at both the treatments, suggesting that environmentally relevant MDMA concentrations did not induce deleterious effects to the zebra mussel. PMID:24878561

Parolini, Marco; Magni, Stefano; Binelli, Andrea

2014-09-01

 
 
 
 
241

Small molecule analysis and imaging of fatty acids in the zebra finch song system using time-of-flight-secondary ion mass spectrometry  

Science.gov (United States)

Fatty acids are central to brain metabolism and signaling, but their distributions within complex brain circuits have been difficult to study. Here we applied an emerging technique, time-of-flight secondary ion mass spectrometry (ToF-SIMS), to image specific fatty acids in a favorable model system for chemical analyses of brain circuits, the zebra finch (Taeniopygia guttata). The zebra finch, a songbird, produces complex learned vocalizations under the control of an interconnected set of discrete, dedicated brain nuclei “song nuclei”. Using ToF-SIMS, the major song nuclei were visualized by virtue of differences in their content of essential and non-essential fatty acids. Essential fatty acids (arachidonic acid and docosahexaenoic acid) showed distinctive distributions across the song nuclei, and the 18-carbon fatty acids stearate and oleate discriminated the different core and shell subregions of song nucleus LMAN. Principle component analysis of the spectral data set provided further evidence of chemical distinctions between the song nuclei. By analyzing song nucleus RA at three different ages during juvenile song learning, we obtain the first direct evidence of changes in lipid content that correlate with progression of song learning. The results demonstrate the value of ToF-SIMS to study lipids in a favorable model system for probing the function of lipids in brain organization, development and function. PMID:21496023

Amaya, Kensey R.; Sweedler, Jonathan V.; Clayton, David F.

2011-01-01

242

Líneas cebra: Repercusión radiológica de la acción de los bifosfonatos en el esqueleto inmaduro / Zebra lines: Radiological repercussions of the action of bisphosphonates on the immature skeleton  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Los bifosfonatos son utilizados en el tratamiento de la osteogénesis imperfecta, observándose con ellos una reducción de las fracturas en estos pacientes. Sin embargo, el uso de dichos fármacos en el esqueleto inmaduro de estos pacientes da lugar a la formación de unas bandas lineales hiperdensas vi [...] sibles radiológicamente, llamadas líneas cebra o zebra lines. Presentamos el caso de un paciente con osteogénesis imperfecta que inició tratamiento con bifosfonatos a los 10 años de edad y que al cabo de 2 años ya mostraba dichas imágenes radiológicas. Abstract in english The bisphosphonates are used in the treatment of osteogenesis imperfecta, with a reduction in fractures in these patients observed with their use. However, the use of these drugs on the immature skeleton in these patients results in the formation of some radiologically visible hyperdense linear band [...] s called zebra lines. We present the case of a patient with osteogenesis perfecta who started treatment with bisphosphonates at 10 years of age and after 2 years already showed these radiological images.

I., Etxebarria-Foronda; L., Gorostiola-Vidaurrazaga.

2013-03-01

243

A newly discovered superoantero-orbital sinus connecting to the interaural canal may play a role in zebra finch hearing  

DEFF Research Database (Denmark)

The middle ears of birds are acoustically connected through an air-filled pathway, the interaural canal (IAC), which allows sound to propagate internally from one ear to the other and considerably enhance the cues for directional hearing. The enhancement of the directional cues depends on the amplitude gain and time delay through IAC. Theoretically, different combinations of frequency dependent gains and delays produce very different directionalities of the ears but it is still uncertain how gain and delay can be shaped by evolution. We have discovered that a large forehead sinus superoanterior to the orbits (superoantero-orbital sinus, SAOS) connects to the IAC via a tube inferomedial to the orbits (IMT). SAOS has a very complex shape with connections through an arc over the eye to the bullae of each ear and also to two smaller lateral sinuses in front of each eye. The contribution of this structure to auditory sensitivity has not been studied previously. We hypothesized that the extra air volume could form a resonator influencing the gain and delay of IAC. We tested the hypothesis by measuring sound transmission through IAC of zebra finches before and after filling the SAOS with a silicone impression medium. Six out of seven individuals showed an effect of filling the SAOS or the IMT on directionality and overall auditory sensitivity. The SAOS therefore does seem to have an effect on gain and delay in the interaural canal as well as on auditory sensitivity. The effect, however, was complex and either significantly changed the gain by up to 10 dB in the frequency range below about 2-3 kHz and/or in a narrow band around 4-6 kHz. Although we verified the fillings by post-experimental dissection, it was difficult to determine exactly to what degree the different components were filled. Thus differential filling and/or blockage of the complex system may be the reason for complexity of the results. Future experiments aim for better control of the cavity filling.

Christensen-Dalsgaard, Jakob; Larsen, Ole Næsbye

244

Combined roles of contact stimulant and deterrents in assessment of host-plant quality by ovipositing zebra swallowtail butterflies.  

Science.gov (United States)

Zebra swallowtail (Eurytides marcellus) butterflies are stimulated to oviposit by a single compound, 3-caffeoyl-muco-quinic acid (1). Analysis of the aqueous extracts of the leaves of the host. Asimina triloba, showed that they contained stimulant 1, its isomer (2), and the flavonoids rutin (3) and nicotiflorine (4) as major components. We compared the concentrations of compounds 1-4 in terminal leaves (TL) and expanded leaves (EL) of the host plants at four different times throughout the growing season. In spring, the concentration of 1 was highest in TLs, and flavonoids were not detectable or present at low levels. As the season progressed, however, the concentrations of flavonoids increased, reached maxima by late summer, and then decreased as the plants started senescing. There were also significant differences in the concentrations of these compounds between TLs and ELs. In a choice assay with model leaves, we tested equivalent amounts of post-dichloromethane aqueous extracts made in spring (May) and in fall (September). September extracts received significantly fewer approaches and eggs. In greenhouse experiments with potted A. triloba plants, the butterflies chose some leaves to lay eggs, while others were rejected or ignored. Analyses showed that the concentrations of compound 1 were not significantly different in the three kinds of leaves. The flavonoids (3 and 4), however, were significantly higher in the leaves that were ignored. Multiple-choice tests using model plants suggested that concentrations of both flavonoids and stimulant were important in assessing host suitability. There was a gradual decrease in approaches as the concentration of 1 decreased. Higher amounts of flavonoids deterred egg laying even in the presence of high concentrations of stimulant 1. At lower concentrations of 1, the addition of low doses of flavonoids deterred egg laying. Thus, the results suggest that the butterflies use both qualitative and quantitative information about these compounds to assess host quality. This behavior may have evolved to take advantage of seasonal variation in the chemistry of their host, A. triloba. PMID:12757326

Haribal, Meena; Feeny, Paul

2003-03-01

245

The Black Cuckoo-Shrike Campephaga flava: A new record for the Mountain Zebra National Park and the Cradock district, Cape Province  

Directory of Open Access Journals (Sweden)

Full Text Available The avifauna of the Mountain Zebra National Park (MZNP has been recorded over a period of some two decades (Skead 1965, Koedoe 8: 1-40; Penzhorn & Bronkhorst 1976, Koedoe 19: 171-174; Penzhorn 1977, Koedoe 20: 205-207; Grobler & Bronkhorst 1981, Koedoe 24: 199-203. Collett (1982 Southern Birds 9: 1-65 has summarised all the available information on the avifauna of the Cradock district assembled since the turn of the century. Although 203 species are recorded from the MZNP by these authors (and a further four in the roneoed checklist for the park (Anon, updated, National Parks Board of Trustees, roneod, 15 pp no mention is made of the Black Cuckoo-Shrike Campephaga flava. Collett (1982 does not list it for the Cradock district.

I.A.W Macdonald

1984-12-01

246

On the origin of zebra textures in Mississippi Valley-Type Pb-Zn Deposits with a special emphasis on the San Vicente Mine, Peru  

Science.gov (United States)

Alternating dark and white bands are common features of ore hosting dolostones which are generally termed zebra textures. Worldwide these structures occur in ore deposits of the Mississippi Valley-Type (MVT). This type of deposit frequently develops in hydrothermal systems located in the flanks of foreland basins. In most MVT ore deposits it is possible to distinguish between different stages which occur during the formation of the zebra textures and the precipitation of the ore-minerals (mostly Sphalerite and Galena). As the dark and white bands consist nearly completely of dolomite, despite the colour, the only clearly recognisable difference is the grain size. Today there are several theories which try to explain the formation of this kind of structure, for example by dissolution-precipitation (FONTBONTé et al., 1993) or by displacive vein growth (MERINO et al., 2006). Based on these theories and additional analytical findings, we want to develop a numerical model to study the banding and mineralisation. This model should include all processes from dolomitization, to the development of the zebra textures and finally the precipitation of Sphalerite and Galena. Using optical microscope and SEM, we found, that there are also differences in the shapes of the grain boundaries of the fine grained dark (lobate) and coarse grained white bands (polygonal). Furthermore, there is a large number of second-phase particles, namely apatite, iron oxides and organic matter, present in the dark bands. Often these particles are lined up at the grain boundaries. These insights lead to the hypothesis that the grain growth in the dark bands is influenced by obstacles that reduce the growth rate and therefore lead to a bifurcation of this rate in the system. For the modelling the microdynamic simulation software ELLE is used to perform a 2D-simulation at the scale of a thin section. This simulation uses a boundary-model coupled with a lattice-particle-code (BONS et al. 2001). The grain boundaries move according to a rate law based on dissolution-precipitation processes as a function of differences in surface energy. Layered distributions of particle densities are initially set as a background. With this simple simulation of grain growth influenced by particle distributions we show, that this process is able to develop structural patterns that are very similar to those present in the natural samples from the San Vicente Mine in Peru. References BONS P D, KOEHN D, and JESSELL W (2008) Microdynamic Simulation. Springer-Verlag Berlin Heidelberg FONTBONTé L (1993) Self-organization fabrics in carbonate-hosted ore deposits: the example of diagenetic crystallization rhythmites (DCRs), In: Current research in geology applied to ore deposits. Proceedings of the Second Biennial SGA Meeting, Granada, Spain, p. 11 -14 MERINO E, CANALS A, and FLECHTER R C (2006) Genesis of self-organized zebra textures in burial dolomites: Displacive veins, induced stress, and dolomitization. Geologica Acta, Vol. 4 No. 3, p. 383-393

Kelka, Ulrich; Koehn, Daniel

2014-05-01

247

Uptake and release kinetics of 134Cs by goldfish (Carassius auratus) and 137Cs by zebra fish (Brachydanio rerio) in controlled aquatic environment  

International Nuclear Information System (INIS)

The uptake and release kinetics of 134Cs by Goldfish (Carassius auratus) and 137Cs by Zebra Fish (Brachydanio rerio) from aquatic media of different ionic compositions and temperature was studied in controlled laboratory conditions. The accumulation of radiocesium in the case of Brachydanio rerio is observed to be strongly dependent on the potassium ion concentration of the aquatic medium, but in the case of Carassius auratus this dependence is quite weak. The biological half-lives of the cesium isotopes incorporated into the fish investigated in the present work vary from 19 to 80 days and are influenced by the temperature and the ionic composition of the aquatic medium. (author) 19 refs.; 1 fig.; 3 tabs

248

Genomic organization and molecular phylogenies of the beta (? keratin multigene family in the chicken (Gallus gallus and zebra finch (Taeniopygia guttata: implications for feather evolution  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The epidermal appendages of reptiles and birds are constructed of beta (? keratins. The molecular phylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian ?-keratin genes are closely related to those of birds, the published genomes of the chicken and zebra finch provide an opportunity not only to compare the genomic organization of their ?-keratins, but to study their molecular evolution in archosaurians. Results The subfamilies (claw, feather, feather-like, and scale of ?-keratin genes are clustered in the same 5' to 3' order on microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and that the monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyletic cluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for the chicken demonstrates that all feather ?-keratin clades are expressed. Conclusions Similarity in the overall genomic organization of ?-keratins in Galliformes and Passeriformes suggests similar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as the paravian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendages in the lineage leading to birds was accompanied by duplication and divergence of an ancestral ?-keratin gene cluster. As morphological diversification of epidermal appendages occurred and the ?-keratin multigene family expanded, novel ?-keratin genes were selected for novel functions within appendages such as feathers.

Sawyer Roger H

2010-05-01

249

The combined effect of lead exposure and high or low dietary calcium on health and immunocompetence in the zebra finch (Taeniopygia guttata)  

International Nuclear Information System (INIS)

The widespread contamination by lead and the acidification of the environment ask for a better understanding of the effects of the interaction between lead and calcium on various aspects of health, including disease defense, in wildlife. Here, we investigated the effects of chronic exposure to sublethal levels of lead, combined with high or low dietary calcium, on health and several components of immunity in male and female zebra finches (Taeniopygia guttata). Thirty individuals of each sex were randomly assigned to three groups: a control group, a group exposed to lead with an additional calcium source (i.e. grit) and a group exposed to lead without access to an extra calcium source. Lead was administered as lead acetate via the drinking water (20 ppm) for 38 consecutive days. Exposure to lead increased significantly the concentrations of lead in kidney and bone in individuals of the experimental groups. Furthermore, the lack of a calcium supplement significantly enhanced the uptake of lead. Lead did not affect health indices such as hematocrit, spleen mass and body mass, nor the adrenal stress response. Cell-mediated immune responsiveness, assessed by a delayed-type hypersensitivity response to phytohaemagglutinin, was also not affected by lead exposure. On the other hand, lead exposure did significantly suppress the secondary humoral immune response towards sheep red blood cells in females, but only when the additional calcium source was not available. This effect was not found in males, suggesting sexual differences in susceptibility of humoral immunity to lead treatment in zebra finches. - Male and female finches may respond to lead differently

250

Discovery of a novel functional leptin protein (LEP) in zebra finches: evidence for the existence of an authentic avian leptin gene predominantly expressed in the brain and pituitary.  

Science.gov (United States)

Leptin (LEP) is reported to play important roles in controlling energy balance in vertebrates, including birds. However, it remains an open question whether an authentic "LEP gene" exists and functions in birds. Here, we identified and characterized a LEP gene (zebra finch LEP [zbLEP]) encoding a 172-amino acid precursor in zebra finches. Despite zbLEP showing limited amino acid sequence identity (26%-29%) to human and mouse LEPs, synteny analysis proved that zbLEP is orthologous to mammalian LEP. Using a pAH32 luciferase reporter system and Western blot analysis, we demonstrated that the recombinant zbLEP protein could potently activate finch and chicken LEP receptors (zbLEPR; cLEPR) expressed in human embryonic kidney 293 cells and enhance signal transducer and activator of transcription 3 phosphorylation, further indicating that zbLEP is a functional ligand for avian LEPRs. Interestingly, quantitative real-time RT-PCR revealed that zbLEP mRNA is expressed nearly exclusively in the pituitary and various brain regions but undetectable in adipose tissue and liver, whereas zbLEPR mRNA is widely expressed in adult finch tissues examined with abundant expression noted in pituitary, implying that unlike mammalian LEP, finch LEP may not act as an adipocyte-derived signal to control energy balance. As in finches, a LEP highly homologous to zbLEP was also identified in budgerigar genome. Strikingly, finch and budgerigar LEPs show little homology with chicken LEP (cLEP) previously reported, suggesting that the so-called cLEP is incorrect. Collectively, our data provide convincing evidence for the existence of an authentic functional LEP in avian species and suggest an important role of brain- and pituitary-derived LEP played in vertebrates. PMID:24823393

Huang, Guian; Li, Juan; Wang, Hongning; Lan, Xinyu; Wang, Yajun

2014-09-01

251

Leaf variegation in the rice zebra2 mutant is caused by photoperiodic accumulation of tetra-cis-lycopene and singlet oxygen.  

Science.gov (United States)

In field conditions, the zebra2 (z2) mutant in rice (Oryza sativa) produces leaves with transverse pale-green/yellow stripes. It was recently reported that ZEBRA2 encodes carotenoid isomerase (CRTISO) and that low levels of lutein, an essential carotenoid for non-photochemical quenching, cause leaf variegation in z2 mutants. However, we found that the z2 mutant phenotype was completely suppressed by growth under continuous light (CL; permissive) conditions, with concentrations of chlorophyll, carotenoids and chloroplast proteins at normal levels in z2 mutants under CL. In addition, three types of reactive oxygen species (ROS; superoxide [O??], hydrogen peroxide [H?O?], and singlet oxygen [¹O?]) accumulated to high levels in z2 mutants grown under short-day conditions (SD; alternate 10-h light/14-h dark; restrictive), but do not accumulate under CL conditions. However, the levels of lutein and zeaxanthin in z2 leaves were much lower than normal in both permissive CL and restrictive SD growth conditions, indicating that deficiency of these two carotenoids is not responsible for the leaf variegation phenotype. We found that the CRTISO substrate tetra-Cis-lycopene accumulated during the dark periods under SD, but not under CL conditions. Its accumulation was also positively correlated with ¹O? levels generated during the light period, which consequently altered the expression of ¹O?-responsive and cell death-related genes in the variegated z2 leaves. Taking these results together, we propose that the z2 leaf variegation can be largely attributed to photoperiodic accumulation of tetra-cis-lycopene and generation of excessive ¹O? under natural day-night conditions. PMID:22134723

Han, Su-Hyun; Sakuraba, Yasuhito; Koh, Hee-Jong; Paek, Nam-Chon

2012-01-01

252

Organochlorine and trace element contamination in wintering and migrating diving ducks in the southern Great Lakes, USA, since the zebra mussel invasion  

Science.gov (United States)

Because of the potential for increased trophic transfer of contaminants by zebra mussels (Dreissena sp.) to higher trophic levels, we collected four species of waterfowl (n = 65 ducks) from four locations in Lake Erie, Lake St. Clair, and Lake Michigan, USA, between 1991 and 1993 for organochlorine contaminant and trace element analyses. Geometric mean concentrations of total polychlorinated biphenyls (PCBs) and p,pa??-dichlorodiphenyldichloroethylene (DDE) were 1.35 and 0.15 I?g/g wet weight in lesser scaup (Aythya affinis) carcasses and were below known effect levels. Total PCBs in 80% of carcasses, however, were above the U.S. Food and Drug Administration's threshold of 3.0 I?g/g lipid weight for consumption of poultry. With the exception of selenium, trace elements were also at background or no-effect levels. Selenium concentrations in livers of 95% of lesser scaup, 90% of bufflehead (Bucephala albeola), and 72% of common goldeneye (Bucephala clangula) were in the elevated (>10 I?g/g dry wt) or potentially harmful range (>33 I?g/g dry wt). The effects of these high selenium concentrations are unknown but should be investigated further based on reproductive effects observed in field and laboratory studies of dabbling ducks and because lesser scaup populations are declining. Concentrations of total PCBs in dreissenid mussels in western Lake Erie were 10 times higher than in the upper Mississippi River but were similar to concentrations in other industrialized rivers in Europe and the United States. Metal concentrations were similar to other industrialized sites where zebra mussels have been sampled.

Custer, C.M.; Custer, T.W.

2000-01-01

253

Impact of zebra and quagga mussels (Dreissena spp.) on freshwater unionids (Bivalvia: Unionidae) in the Detroit River of the Great Lakes  

Science.gov (United States)

To assess the impact of zebra and quagga mussel (Dreissena spp.) infestation on unionids, unionids (Bivalvia: Unionidae) were sampled in the Detroit River in 1982-1983, before mussels invaded the river, and in 1992 and 1994, after mussels invaded the river. Live unionids at four stations along the southeastern shore accounted for 97% (20 species) of all shells collected in 1982-1983, whereas live unionids accounted for only 10% (13 species) in 1992. A similar decline in live unionids occurred at nine stations along the northwestern shore, except the decline occurred over the three sampling periods: in 1982-83, 84% (22 species) were live; in 1992, 65% (26 species) were live; and, in 1994, only 3% (13 species) were live. The difference in time to near-total mortality of unionids along the southeastern and northwestern shores is attributed to differences in the time of invasion and abundance of zebra mussel veligers in distinct water masses emanating from Lake St. Clair located immediately upstream of the Detroit River. Although individuals of all species of all unionid subfamilies declined between 1982 and 1992/1994, members of the subfamilies Anodontinae and Lampsilinae declined more than Ambleminae. Between 1986 and 1992/1994, five Anodontinae, three Lampsilinae and 0 Ambleminae species have been extirpated from the river due to dreissenid mussel infestation. Numbers of individuals of commonly found species declined more than numbers of individuals of uncommonly found species. However, the number of uncommon species declined 47% (17 to 9) along both the southeastern and northwestern shores, whereas common species remained the same (3 species) along the southeastern shore and declined only 40% (5 to 3 species) along the northwestern shore. This study, and others, suggest that high mortality of unionids can occur between 4 and 6 yr after initial invasion by dreissenids or up to 8 yr depending on water current patterns. Infestation-induced mortality of unionids in the Detroit River is similar to that observed at a few locations in other rivers, but is higher over a larger area than that measured in other rivers to date, probably because the Detroit River was the first to be colonized by dreissenid mussels in North America.

Schloesser, D.W.; Kovalak, W.P.; Longton, G.D.; Ohnesorg, K.L.; Smithee, R.D.

1998-01-01

254

Descripción y variación mensual de las etapas reproductivas de la pepitona Arca zebra (Swainson, 1833) en el banco de Chacopata, península de Araya, estado Sucre, Venezuela / Description and monthly variation in reproductive stages of the clam Arca zebra (Swainson, 1833) in the Chacopata bank, Araya peninsula, Sucre state, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Se estudió la variación mensual (12 meses) de las etapas reproductivas e histológicas en ejemplares adultos de Arca zebra, recolectados en el banco natural de Chacopata, estado Sucre, Venezuela. Las características histológicas del tejido gonadal se describieron en función de los siguientes estadios [...] reproductivos: reposo (0), inicio de la madurez (I), madurez total (II), desove parcial (III), desove total y degeneración (IV). No se encontraron diferencias significativas en la proporción total de sexos, aunque este parámetro difirió significativamente de una relación 1M:1H en algunos meses. La especie presenta asincronía en la maduración de los folículos, sin embargo, el análisis cuantitativo reveló que los estadios II y III estuvieron presentes durante todo el período de muestreo. Se observaron los cinco estadios de maduración gonadal en hembras, pero solamente los estadios I al III en machos. Las frecuencias de los estadios se relacionaron con las variaciones significativas que presentaron los promedios mensuales del diámetro de los folículos y del lumen en ambos sexos. El diámetro promedio de los óvulos maduros fue de 6,00 ± 0,11 ?m, presentando su máima proporció en el estadio II. El incremento del estadio II, observado desde julio hasta septiembre 2002, se correlacionó con aumentos de temperatura, mientras que el incremento del estadio III coincidió con disminuciones de temperatura observados desde octubre de 2002 hasta enero de 2003. Tanto la salinidad como la concentración de clorofila a mostraron escasa variación durante el estudio, indicando que no son factores limitantes durante el proceso reproductivo de la especie. Se concluye que las alteraciones en la temperatura del agua parecen ser el principal factor asociado a las variaciones en el ciclo reproductivo en A. zebra. Abstract in english Monthly variation (12 months) in reproductive stages and histology in adult specimens of Arca zebra harvested from natural bed of Chacopata, Sucre state, Venezuela were studiedied. The histological characteristics of gonadal tissue were described according to their reproductive stages: resting (0), [...] onset of maturity (I), total maturity (II), partial spawning (III), total spawning and degeneration (IV). There were no significant differences in the total proportion of sexes, although there was significant differences in the 1M:1F relation in some months. The species presents asynchrony in the maturation of the follicles, however, quantitative analysis shows that while stages II and III were present throughout the sampling period. Males were observed in stages 0 and IV, but in females. Changes in the frequency of the stages were associated with significant variations presented the monthly mean diameter of follicles and the lumen in both sexes, were always higher in females. The average diameter of mature eggs was 5,88 ± 0,11 ?m, showing its highest proportion in stage II. The increase in stage II observed from July to September 2002 was correlated with increases in temperature, while the increase of stage III coincides with the observed temperature decreases from October 2002 to January 2003. Salinity showed little variation, and the chlorophyll remained constant during the study, indicating that there is a limiting factor, so it is suggested that temperature is the main factor associated with reproductive changes in A. zebra.

María, Lista; Antulio, Prieto; Carlos, Velásquez; César, Lodeiros; Vanessa, Acosta; Yelipza, Longart; Gilma, Hernández.

255

Auditory-dependent vocal recovery in adult male zebra finches is facilitated by lesion of a forebrain pathway that includes the basal ganglia.  

Science.gov (United States)

The integration of two neural pathways generates learned song in zebra finches. The vocal motor pathway (VMP) is a direct connection between HVC (proper name) and the robust nucleus of the arcopallium (RA), whereas the anterior forebrain pathway (AFP) comprises an indirect circuit from HVC to RA that traverses the basal ganglia. Partial ablation (microlesion) of HVC in adult birds alters the integration of VMP and AFP synaptic input within RA and destabilizes singing. However, the vocal pattern shows surprising resilience because birds subsequently recover their song in approximately 1 week. Here, we show that deafening prevents vocal recovery after HVC microlesions, indicating that birds require auditory feedback to restore/relearn their vocal patterns. We then tested the role of the AFP (basal ganglia circuit) in this feedback-based recovery by ablating the output nucleus of the AFP [lateral magnocellular nucleus of the anterior nidopallium (LMAN)]. We found that LMAN ablation after HVC microlesions induced a sudden recovery of the vocal pattern. Thus, the AFP cannot be the neural locus of an instructive/learning mechanism that uses auditory feedback to guide vocal recovery, at least in this form of adult vocal plasticity. Instead, the AFP appears to be the source of the variable motor patterns responsible for vocal destabilization. In part, auditory feedback may restore song by strengthening the VMP component of synaptic input to RA relative to the AFP component. PMID:17989295

Thompson, John A; Wu, Wei; Bertram, Richard; Johnson, Frank

2007-11-01

256

Evidence for cholinergic participation in the control of bird song; acetylcholinesterase distribution and muscarinic receptor autoradiography in the zebra finch brain  

International Nuclear Information System (INIS)

Brain regions thought to be involved in the control of song in the zebra finch (Poephila guttata), were examined histochemically using the Karnovsky and Roots direct-coloring method for the detection of acetylcholinesterase (AChE) and the autoradiographic method for the localization of muscarinic cholinergic receptors following injection of tritiated quinuclidinyl benzilate (3H QNB). All presently identified vocal control nuclei in both males and females contain AChE. These nuclei include Area X, magnocellular nucleus of the anterior neostriatum (MAN), nucleus interface (NIF), caudal nucleus of the hyperstriatum ventrale (HVc), intercollicular nucleus (ICo), nucleus uva, robust nucleus of the archistriatum (RA), and tracheosyringeal portion of the hypoglossal nerve nucleus (nXIIts). All nuclei except Area X contain mostly AChE-synthesizing cell bodies. All of these nuclei contain some AChE in the neuropil, with particularly intense staining in Area X, the surrounding LPO, and the dorsomedial portion of ICo. In agreement with this description are very high concentrations of 3H QNB in both Area X and the dorsomedial ICo. HVc also appears specifically labeled. Evidence from these two histological technique suggests that efferent projections of most vocal control area may utilize acetylcholine, and that several of the vocal control nuclei may themselves receive muscarinic cholinergic projection. In Area X, there are sex differences of AChE neuropil staining. This evidence suggesting that sexually dimorphic projections to or within Area X are cholinergic or cholinoceptive

257

Are there species-universal categories in bird song phonology and syntax? A comparative study of chaffinches (Fringilla coelebs), zebra finches (Taenopygia guttata), and swamp sparrows (Melospiza georgiana).  

Science.gov (United States)

Previous studies of learned bird song have suggested the existence of species-universal patterns in song organization: clear clusters in produced songs that do not vary within a species. Here the authors combine a computational method of comparing songs with statistical methods of assessing cluster structure to investigate this issue in a more quantitative manner. The authors first analyze song phonology and then examine song syntax at a population level in 3 species with very different song structure: chaffinches (Fringilla coelebs), zebra finches (Taenopygia guttata), and swamp sparrows (Melospiza georgiana). The authors used a dynamic time-warping algorithm to compare song elements, which closely matched the judgments of human observers. Clustering tendency and validation statistics showed that broad phonological categories existed in all 3 species, but these categories explained no more than half of the overall phonological variation. The authors developed a novel statistic to assess syntactical structure, which indicated that element transitions were not randomly distributed. In the clearest case, in chaffinches, this could be explained by syllables being linked to certain positions within the song. These results demonstrate measures of song organization that can be applied across species, enhancing the potential of comparative studies. PMID:20175600

Lachlan, R F; Verhagen, L; Peters, S; Cate, C Ten

2010-02-01

258

Uptake and bioaccumulation of platinum group metals (Pd, Pt, Rh) from automobile catalytic converter materials by the zebra mussel (Dreissena polymorpha).  

Science.gov (United States)

The uptake and bioaccumulation of the platinum group metals (PGM) platinum (Pt), palladium (Pd), and rhodium (Rh) by the zebra mussel (Dreissena polymorpha) were investigated in exposure studies using ground material from unused automobile catalytic converters as metal source. The mussels were exposed to the metals in tap water or humic water. In the soft tissue samples of exposed mussels mean Pt levels ranged in dependence on the type of tank water and the exposure period (6, 9, or 18 weeks) between 780 and 4300 ng/g, the Pd levels ranged between 720 and 6300 ng/g, and the Rh levels ranged between 270 and 1900 ng/g. In contrast, the control mussels had metal concentrations of <20 ng/g (Pt), <50 ng/g (Pd), and <40 ng/g (Rh). Considerably higher PGM levels were found in the exposed mussels of the humic water group than in those of the tap water group. Although there is a cumulative increase of the PGM concentrations in the environment since the introduction of the automobile catalyst more than 20 years ago, only little information about the PGM contamination in the biosphere, especially the fauna, is available. Due to the high capacity of D. polymorpha to accumulate PGM, this bivalve could be used as a potential sentinel for monitoring the noble metals in aquatic ecosystems. PMID:15820726

Zimmermann, Sonja; Messerschmidt, Jürgen; von Bohlen, Alex; Sures, Bernd

2005-06-01

259

Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: a 2-year integrative field study of seasonal and pollution-induced variations.  

Science.gov (United States)

Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools. PMID:17313981

Guerlet, Edwige; Ledy, Karine; Meyer, Antoinette; Giambérini, Laure

2007-03-30

260

Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: A 2-year integrative field study of seasonal and pollution-induced variations  

Energy Technology Data Exchange (ETDEWEB)

Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools.

Guerlet, Edwige [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Ledy, Karine [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Meyer, Antoinette [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Giamberini, Laure [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France)]. E-mail: giamb@univ-metz.fr

2007-03-30

 
 
 
 
261

Daily behaviour can differ between colour morphs of the same species: a study on circadian activity behaviour of grey and pied zebra finches.  

Science.gov (United States)

To investigate if the plumage colour mutation relates to circadian activity behaviour in the zebra finch, Taeniopygia guttata, wild type grey and pied mutant males were sequentially subjected for three weeks each to 12 h light:12 h darkness (12L:12D) and constant dim light (LL(dim)) condition. During the first 3 h of the 12 h day, pied finches were significantly greater active than grey finches. Also, as compared to grey, pied finches had longer activity duration in the day, with early activity onsets and late activity offsets. This was changed under free-running condition (LL(dim)), when the activity later in the subjective day (clock hour 9 and 11) was significantly greater in grey than in pied finches.Two colour morphs differed in daily activity profile, but not in the total daily activity or circadian rhythm period. Results suggest that greyzebra finches represent late chronotype, and could perhaps be better adapted to a seemingly stressful environment, such as low intensity LL(dim) in the present study. PMID:24851415

Mishra, Ila; Trivedi, Amit Kumar; Kumar, Vinod

2014-05-01

262

Multi-biomarker approach to investigate the state of contamination of the R. Lambro/R. Po confluence (Italy) by zebra mussel (Dreissena polymorpha).  

Science.gov (United States)

This study assesses the response of the zebra mussel (Dreissena polymorpha) to chemical pollution derived from the R. Lambro/R. Po confluence, which is one of the most polluted aquatic environments in Europe. The mussels were tested under laboratory conditions to water sampled in the spring and fall at three sites located upstream or downstream of the confluence or directly in R. Lambro alone. We performed on mussel specimens a biomarker battery composed by eight different assays: single cell gel electrophoresis, apoptosis determination, the micronucleus test and Neutral Red retention, as well as catalase, superoxide dismutase, glutathione peroxidase and glutathione transferase activities. We also evaluated the bioaccumulation of several organic pollutants (PAHs, PCBs, DDTs, HCHs and HCB) to characterize the sampling sites. Significant increases in DNA strand breaks, apoptosis and micronuclei were observed, with no significant seasonal differences. We observed a clear induction of the enzyme activities measured in the spring, but the enzymatic activity trend in the fall was very complex, with several enzymes returning to baseline levels of activity, suggesting a possible seasonal change in chemical mixture characteristics. PMID:20202670

Binelli, A; Cogni, D; Parolini, M; Provini, A

2010-04-01

263

Adverse effects of fipronil on avian reproduction and development: maternal transfer of fipronil to eggs in zebra finch Taeniopygia guttata and in ovo exposure in chickens Gallus domesticus.  

Science.gov (United States)

Two studies were carried out to examine the impact of maternal fipronil exposure on embryonic and offspring development. In the first study, breeding female zebra finches were orally dosed with single sublethal levels of fipronil (1, 5, and 10 mg/kg body weight) to determine behavioural and developmental consequences on chicks following maternal pesticide exposure. Significant levels of fipronil and fipronil-sulfone residues were detected in eggs laid by females in all dosed groups, however, these were undetectable in eggs laid 13 days after treatment. The level of sulfone detected in eggs was consistently higher than that of the parent fipronil compound. Of the seven eggs laid in the treatment groups, only one (14%) chick hatched and this was from the lowest dose group. This chick was severely underdeveloped at 10 days of age in comparison to control chicks and fiproles were detected in brain, liver, and adipose tissues collected following euthanasia of this individual. In contrast, there was 100% hatchability of control group eggs and all chicks fledged nests on schedule. In the second study, domestic chicken eggs were injected with 5.5, 17.5, and 37.5 mg/kg egg weight of fipronil directly into the yolk sac on day 12 of incubation. Treatment did not affect hatching success, however, behavioural and developmental abnormalities were observed in hatchlings from the highest dose group. These chicks also demonstrated reduced feeding rates, as indicated by reduced body mass at 48 h period post hatch. Both fipronil and fipronil-sulfone residues were detected in brain and liver tissue of hatchlings at all pesticide dose levels tested. PMID:21327488

Kitulagodage, Malsha; Buttemer, William A; Astheimer, Lee B

2011-06-01

264

Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu  

International Nuclear Information System (INIS)

Highlights: • Mussels exposed to algal/sediment-Cu have different size-related Cu accumulation. • Size-related Cu accumulation in mussels could be more dependant on algal-Cu uptake. • Importance of algal/sediment-Cu to Cu bioaccumulation varies with mussel body size. • Cu sources (algae and sediments) should be considered in “mussel watch” programs. • Cu stable isotope offers many advantages in Cu bioaccumulation studies. -- Abstract: Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope (65Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5 mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors

265

Attenuating effects of natural organic matter on microcystin toxicity in zebra fish (Danio rerio) embryos -- benefits and costs of microcystin detoxication.  

Science.gov (United States)

To contribute to the understanding of joined factors in the environment, impact of pure microcystins (-RR and -LF) on zebra fish (Danio rerio) embryos were investigated individually and in combination with a natural organic matter (NOM). The applied NOM was a reverse osmosis isolate from Lake Schwarzer See (i.e., Black Lake, BL-NOM). Teratogenic effects were evaluated through changes in embryonic development within 48 h of exposure. Detoxication activities were assessed by the activities of phase II biotransformation enzymes, soluble and microsomal glutathione S-transferase (s, mGST). Oxidative stress was assessed by determining both the production of hydrogen peroxide and by analyzing the activities of the antioxidative enzymes, guajacol peroxidase (POD), catalase (CAT), glutathione peroxidase (GPx), and the glutathione restoring enzyme glutathione reductase (GR). Energetic costs were evaluated by determining contents of fat, carbohydrates, and proteins in both exposed and control embryos. BL-NOM attenuated toxic effects of MC-LF and MC-RR verified by less pronounced teratological effects within 24 h, in particular, as well as less rise in the activity of s-GST, when compared with embryos exposed to either pure toxins or in combination with organic matter. BL-NOM also diminished oxidative effects caused by MC-LF; however, it failed to attenuate oxidative stress caused by MC-RR. Content of lipids was significantly reduced in exposed embryos following a trend similar to that obtained with teratological and enzymatic assays confirming the attenuating effect of BL-NOM. Physiological responses to microcystins and NOM required energetic costs, which were compensated to the expense of the energy resources of the yolk, which in turn might affect the normal development of embryos. PMID:16463263

Cazenave, Jimena; Bistoni, María de Los Angeles; Zwirnmann, Elke; Wunderlin, Daniel Alberto; Wiegand, Claudia

2006-02-01

266

Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: A 2-year integrative field study of seasonal and pollution-induced variations  

International Nuclear Information System (INIS)

Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools

267

Bioaccumulation of heavy metals in the zebra mussel Dreissena polymorpha in the rivers Danube and Drau and its role as a bioindicator organism; Schwermetallbelastung von Dreissena polymorpha in Donau und Drau und ihre Bedeutung als Bioindikator  

Energy Technology Data Exchange (ETDEWEB)

Goal and scope. This study was undertaken to investigate the differences in heavy metal burden between the organisms and environmental compartments and to evaluate the role of Dreissena polymorpha as a bioindicator organism. Methods. The concentrations of zinc, copper, cadmium and lead in whole soft body and selected tissues of D. polymorpha at two river habitats in Austria were examined using atomic absorption spectroscopy (AAS). Concentrations in organisms were compared to those in sediment and water. Results and conclusion. Zebra mussels of the river Drau showed generally higher heavy metal concentrations as compared to mussels of the river Danube and contained elevated zinc and cadmium levels as compared to metal concentrations found in soft tissues of zebra mussels from uncontaminated sites in Germany and The Netherlands. The essential metals zinc and copper were mainly accumulated in gills, foot and byssal gland tissue of the mussel, in contrast to the non-essential metals cadmium and lead which were found predominantly in the midgut gland. The heavy metal concentrations in both, sediments and mussel tissue, were higher than in water samples. There was no correlation between the concentrations in water and in the organisms except for zinc. In contrast, correlations were found between concentrations in sediments and mussel soft tissue. Recommendation and perspective. Further investigations should include the examination of sediments and consider the mechanism of food uptake to assess the role of D. polymorpha as a bioindicator organism. (orig.)

Luschuetzky, E.F. [Univ. Wien, Inst. fuer Zoologie, Abt. fuer Ultrastrukturforschung und Elektronenmikroskopie, Wien (Austria)

2005-07-01

268

Comparison of acute toxicity of process chemicals used in the oil refinery industry, tested with the diatom Chaetoceros gracilis, the flagellate Isochrysis galbana, and the zebra fish, Brachydanio rerio  

International Nuclear Information System (INIS)

Chemicals under the trade names Nalco 537-DA, Nalco 625, Nalco 7607, Nalco 5165, Ivamin, and technical monoethanolamine are used extensively in the oil refinery industry. Aquatic toxicity tests were conducted using zebra fish fry (Brachydanio rerio) and the unicellular algae Isochrysis galbana (a flagellate) and Chaetoceros gracilis (a diatom). Inhibition of cell division, chlorophyll content, and 14CO2 uptake in the algae were sensitive end points. The effective concentrations (EC50s) of growth inhibition were 0.1 mg/L (Ivamin; I. galbana), 0.8 mg/L (Nalco 7607; I. galbana), 6 mg/L (Nalco 625; I. galbana), 10 mg/L (Nalco 5165; C. gracilis), and 15 mg/L (Nalco 537-DA; C. gracilis). The lethal concentrations (LC50s) (96 h) toward zebra fish fry was 1 mg/L for Nalco 7607, 6.5 mg/L for Nalco 537-DA, 7.1 mg/L for Nalco 625, and 20 mg/L for Ivamin 803. Monoethanolamine had an LC50 higher than 5,000 mg/L. Nalco 5165 was not tested on fish fry. The heartbeat frequency of fish embryos was reduced by 2.5 mg/L Nalco 537-DA, but this was an insensitive end point for the other chemicals

269

Elementos traza detectados por plasma inductivamente acoplado (ICP) en pepitonas, Arca zebra (Mollusca, Arcidae) de dos localidades costeras del estado Sucre, Venezuela / Trace elements detected by Inductively Coupled Plasma (ICP) in Turkey wing, Arca zebra (Mollusca, Arcidae) from two coastal locations of Sucre State, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Los metales pesados juegan un papel importante en la dinámica de los procesos químicos y ambientales en las zonas costeras. Estos provienen de aportes naturales y antropogénicos y pueden ser bioacumulados en organismos acuáticos, en los que se encuentran como elementos traza, y tienen potenciales ef [...] ectos tóxicos a quienes los consuman, principalmente al hombre como último eslabón de la cadena alimenticia. La gravedad del daño depende del grado y el tiempo de exposición a dichos elementos. Se determinó la concentración de metales pesados (Mg, Cu, Mn, Mo, Ni y Fe) por Plasma Inductivamente Acoplado (ICP) en la pepitona, Arca zebra (Mollusca, Bivalvia, Arcidae), provenientes de las inmediaciones de Caimancito y Chacopata (municipio Cruz Salmerón Acosta, estado Sucre, Venezuela). En Caimancito, las mayores concentraciones de casi todos los metales se detectaron en septiembre, a excepción del Mg que fue observada en febrero. En Chacopata, las concentraciones más elevadas se observaron en el mes de octubre (Mg, Mn y Ni), septiembre (Cu), diciembre (Fe) y en enero (Mo). No se encontraron diferencias significativas entre las localidades, mientras que existen diferencias significativas entre meses. Al momento no existen normas o regulaciones venezolanas que establezcan límites máximos de concentración de los metales analizados en moluscos bivalvos procesados o frescos, que permitan establecer comparaciones con los resultados obtenidos. Sin embargo, en base a normas internacionales, las concentraciones medidas de metales pesados en pepitonas no rebasaron los límites permitidos para consumo humano. Abstract in english Heavy metals play an important role in the dynamics of chemical and environmental processes in the coastal zones. They originate from natural and anthropogenic sources and can be bioaccumulated in aquatic organisms, where they are found as trace elements, and have potential toxic effects to those wh [...] o consume them, mainly to humans as the last link in the food chain. The severity of damage depends on the degree and time of exposure to these elements. The concentration of heavy metals (Mg, Cu, Mn, Mo, Ni and Fe) was estimated by Inductivelly Coupled Plasma (ICP) in the Turkey wing, Arca zebra (Mollusca, Bivalvia, Arcidae), from the vicinity to Caimancito and Chacopata (Municipality Cruz Salmerón Acosta, Sucre state, Venezuela). In Caimancito, higher concentrations of almost all metals were detected in September, except for Mg which was registered in February. In Chacopata, the highest concentrations were observed in October (Mg, Mn and Ni), September (Cu), December (Fe) and January (Mo). No significant differences were found between localities, while there were significant differences among months. At present there are not Venezuelan norms or regulations establishing the maximum concentration limits for the analyzed heavy metals in fresh or processed bivalve mollusks, which may enable comparisons with the obtained results. However, based upon international norms, the measured concentrations of heavy metals in Turkey wing apparently do not represent a threat for human consumption.

Vilma, Lanza; Ildemaro, Martínez; Osmicar, Vallenilla; Julia, Márquez; Arquímedes, González; Jesús, Gamboa; José, Alió.

2011-09-01

270

Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse  

DEFF Research Database (Denmark)

The rich fossil record of equids has made them a model for evolutionary processes. Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr bp). Our data represent the oldest full genome sequence determined so far by almost an order of magnitude. For comparison, we sequenced the genome of a Late Pleistocene horse (43?kyr bp), and modern genomes of five domestic horse breeds (Equus ferus caballus), a Przewalski's horse (E. f. przewalskii) and a donkey (E. asinus). Our analyses suggest that the Equus lineage giving rise to all contemporary horses, zebras and donkeys originated 4.0-4.5?million years before present (Myr bp), twice the conventionally accepted time to the most recent common ancestor of the genus Equus. We also find that horse population size fluctuated multiple times over the past 2?Myr, particularly during periods of severe climatic changes. We estimate that the Przewalski's and domestic horse populations diverged 38-72?kyr bp, and find no evidence of recent admixture between the domestic horse breeds and the Przewalski's horse investigated. This supports the contention that Przewalski's horses represent the last surviving wild horse population. We find similar levels of genetic variation among Przewalski's and domestic populations, indicating that the former are genetically viable and worthy of conservation efforts. We also find evidence for continuous selection on the immune system and olfaction throughout horse evolution. Finally, we identify 29 genomic regions among horse breeds that deviate from neutrality and show low levels of genetic variation compared to the Przewalski's horse. Such regions could correspond to loci selected early during domestication.

Orlando, Ludovic Antoine Alexandre; Ginolhac, Aurélien

2013-01-01

271

Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse.  

DEFF Research Database (Denmark)

The rich fossil record of equids has made them a model for evolutionary processes. Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr bp). Our data represent the oldest full genome sequence determined so far by almost an order of magnitude. For comparison, we sequenced the genome of a Late Pleistocene horse (43 kyr bp), and modern genomes of five domestic horse breeds (Equus ferus caballus), a Przewalski's horse (E. f. przewalskii) and a donkey (E. asinus). Our analyses suggest that the Equus lineage giving rise to all contemporary horses, zebras and donkeys originated 4.0-4.5 million years before present (Myr bp), twice the conventionally accepted time to the most recent common ancestor of the genus Equus. We also find that horse population size fluctuated multiple times over the past 2 Myr, particularly during periods of severe climatic changes. We estimate that the Przewalski's and domestic horse populations diverged 38-72 kyr bp, and find no evidence of recent admixture between the domestic horse breeds and the Przewalski's horse investigated. This supports the contention that Przewalski's horses represent the last surviving wild horse population. We find similar levels of genetic variation among Przewalski's and domestic populations, indicating that the former are genetically viable and worthy of conservation efforts. We also find evidence for continuous selection on the immune system and olfaction throughout horse evolution. Finally, we identify 29 genomic regions among horse breeds that deviate from neutrality and show low levels of genetic variation compared to the Przewalski's horse. Such regions could correspond to loci selected early during domestication.

Orlando, Ludovic Antoine Alexandre; Ginolhac, Aurélien

2013-01-01

272

ZebraMusselLeaflet.indd  

...buy a second hand boat have it cleaned. Guidelines for boat hull cleaning, painting and antifouling are available from Environment and Heritage Service – John McCartney, Calvert House, 23 Castle Place...

273

The zebras come to CERN  

CERN Multimedia

From 23 to 26 November CERN played host to an unusual group of visitors, who arrived in a red-and-white striped camper. On the tenth anniversary of "Les Zèbres”, a children’s broadcast on Swiss radio, the show’s makers invited 8th and 9th grade pupils from Swiss schools to conduct a live broadcast from CERN.   Students in the cryogenic hall: cryolab. Popular Franco-Swiss host Jean-Marc Richard brought Les Zèbres to the Laboratory with a live broadcast. The idea was to let the children themselves host the broadcast. Accompanied by their physics teachers, pupils from junior secondary schools in Golette, Colombières and Drize were given the opportunity to spend half a day at CERN. Each day, one class came to find out about a particular aspect of the Laboratory and then conduct a live broadcast with Jean-Marc Richard from 12:10 to 12:30. The young people, aged 13 to 15, had a chance to explore the Universe of Particles exhibitio...

Laëtitia Pedroso

2010-01-01

274

Macrorhabdus ornithogaster in ostrich, rhea, canary, zebra finch, free range chicken, turkey, guinea-fowl, columbina pigeon, toucan, chuckar partridge and experimental infection in chicken, japanese quail and mice Macrorhabdus ornithogaster em avestruzes, ema, canário, mandarim, galinha, peru, galinha da Angola, pombo doméstico, rolinha, tucano, perdiz de chuckar e infecção experimental em galinha, codorna e camundongo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Since 2000, Macrorhabdus ornithogaster "megabacteriosis" has been diagnosed in the avian diseases laboratory in a diversity of avian species and varied spectrum of disease. The disease in some species (chickens, turkeys, guinea fowls) was clinically characterized by emaciation, prostration, loss of appetite, cachexia and death, with a typically chronic course. A more acute disease was observed in finches (canary-Serinus and zebra-Taeniopygia) and budgerigars (Melopsittacus undulatus). The lar...

Martins, N. R. S.; Horta, A. C.; Siqueira, A. M.; Lopes, S. Q.; Resende, J. S.; Jorge, M. A.; Assis, R. A.; Martins, N. E.; Fernandes, A. A.; Barrios, P. R.; Costa, T. J. R.; Guimara?es, L. M. C.

2006-01-01

275

Interspecific effects of 4A-DNT (4-amino-2,6-dinitrotoluene) and RDX (1,3,5-trinitro-1,3,5-triazine) in Japanese quail, Northern bobwhite, and Zebra finch.  

Science.gov (United States)

The purpose of this study was to assess the toxicological effects of two munition compounds, 4-amino-2,6-dinitrotoluene (4A-DNT) and 1,3,5-trinitro-1,3,5-triazine (RDX), on three different bird species: two common toxicological model species-the Northern Bobwhite (Colinus virginianus) and the Japanese Quail (Coturnix japonica), and a representative passerine-the Zebra Finch (Taeniopygia guttata). Bobwhite were exposed to 4A-DNT at 0, 8, 15, 30, 60, or 150 mg/kg body weight (bw) d by oral gavage for seven days; because the high dose of 4A-DNT was lethal to bobwhite, the maximum dose was changed to 100 mg/kg bw d for Japanese quail and finches to ensure tissue could be used for future toxicogenomic work. RDX was similarly administered at 0, 0.5, 1.5, 3, 6, or 12 mg/kg bw d. Blood was drawn prior to euthanasia for blood cellularity and chemistry analyses. Finches were clearly least affected by 4A-DNT as evidenced by a lack of observable effects. Bobwhite appeared to be the most sensitive species to 4A-DNT as observed through changes in blood cellularity and plasma chemistry effects. Bobwhite appeared to be more sensitive to RDX than Japanese Quail due to increased effects on measures of plasma chemistries. Finches exhibited the greatest sensitivity to RDX through increased mortality and seizure activity. This study suggests that sensitivity among species is chemical-specific and provides data that could be used to refine current avian sensitivity models used in ecological risk assessments. PMID:23161369

Quinn, Michael J; Hanna, Terry L; Shiflett, Alicia A; McFarland, Craig A; Cook, Michelle E; Johnson, Mark S; Gust, Kurt A; Perkins, Edward J

2013-03-01

276

Zebra schlieren optics for leak detection.  

Science.gov (United States)

A modification of schlieren optics was explored as a technique for industrial gas-leak detection. A high-contrast pattern on thin reflecting material was imaged with a zoom lens onto a negative of the same pattern as a method of eliminating the ordinary rays. The geometry of the industrial setting determines the useful spatial frequency of the pattern. PMID:21102869

Peale, R E; Summers, P L

1996-08-01

277

Zebra A5 Leaflet.indd  

...become aggressive if too many females are kept with him in...may be very aggressive towards females and foals while others are...very difficult to introduce additional females. It is therefore recommended that...

278

Adaptive molecular evolution of the Major Histocompatibility Complex genes, DRA and DQA, in the genus Equus  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Major Histocompatibility Complex (MHC genes are central to vertebrate immune response and are believed to be under balancing selection by pathogens. This hypothesis has been supported by observations of extremely high polymorphism, elevated nonsynonymous to synonymous base pair substitution rates and trans-species polymorphisms at these loci. In equids, the organization and variability of this gene family has been described, however the full extent of diversity and selection is unknown. As selection is not expected to act uniformly on a functional gene, maximum likelihood codon-based models of selection that allow heterogeneity in selection across codon positions can be valuable for examining MHC gene evolution and the molecular basis for species adaptations. Results We investigated the evolution of two class II MHC genes of the Equine Lymphocyte Antigen (ELA, DRA and DQA, in the genus Equus with the addition of novel alleles identified in plains zebra (E. quagga, formerly E. burchelli. We found that both genes exhibited a high degree of polymorphism and inter-specific sharing of allele lineages. To our knowledge, DRA allelic diversity was discovered to be higher than has ever been observed in vertebrates. Evidence was also found to support a duplication of the DQA locus. Selection analyses, evaluated in terms of relative rates of nonsynonymous to synonymous mutations (dN/dS averaged over the gene region, indicated that the majority of codon sites were conserved and under purifying selection (dN dS. However, the most likely evolutionary codon models allowed for variable rates of selection across codon sites at both loci and, at the DQA, supported the hypothesis of positive selection acting on specific sites. Conclusions Observations of elevated genetic diversity and trans-species polymorphisms supported the conclusion that balancing selection may be acting on these loci. Furthermore, at the DQA, positive selection was occurring at antigen binding sites, suggesting that a few selected residues may play a significant role in equid immune function. Future studies in natural equid populations will be valuable for understanding the functional significance of the uniquely diverse DRA locus and for elucidating the mechanism maintaining diversity at these MHC loci.

Getz Wayne M

2011-05-01

279

Macrorhabdus ornithogaster in ostrich, rhea, canary, zebra finch, free range chicken, turkey, guinea-fowl, columbina pigeon, toucan, chuckar partridge and experimental infection in chicken, japanese quail and mice / Macrorhabdus ornithogaster em avestruzes, ema, canário, mandarim, galinha, peru, galinha da Angola, pombo doméstico, rolinha, tucano, perdiz de chuckar e infecção experimental em galinha, codorna e camundongo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Desde 2000, diversos casos de infecção e doença por Macrorhabdus ornithogaster (megabacteria) foram diagnosticados no Setor de Doenças das Aves (Escola de Veterinária da UFMG). A doença clínica foi caracterizada por emagrecimento, prostração, perda do apetite, caquexia e morte, em curso crônico, emb [...] ora com forma mais aguda em canários e periquitos. O microrganismo grande, em forma de bastão, visível a partir de 100 aumentos sem e com coloração, pode também ser detectado em aves de aspecto clínico normal, principalmente galinhas, perus, codornas e pombos. Em emas (Rhea), avestruzes (Struthio camelus), canários, mandarins, galinhas da Angola (Numida meleagris) e periquitos Australianos (Melopsittacus undulatus), a severidade da doença foi sempre maior, ocasionando até 100% de mortalidade em alguns plantéis. Na maioria das espécies a doença foi detectada em aves com endo e/ou ectoparasitismo. O cultivo de M. ornithogaster foi obtido em meio sólido (ágar para fungos patogênicos) e subcultivado em meio líquido (thioglicolato), do proventriculo de galinha, galinha da Angola, perdiz de chuckar e canário. O resultado mais surpreendente na microscopia de M. ornithogaster foi a presença de motilidade, detectada tanto de cultivos in vitro quanto de preparações úmidas de in vivo. Diferenças nos aspectos das colônias foram notadas entre os isolados. Infecções experimentais em galinha (SPF) e codorna japonesa permitiram a detecção do organismo nos proventrículos das aves de aspecto normal. Nas codornas, à necropsia notaram-se hemorragias hepáticas. A infecção experimental em camundongos via intraperitoneal resultou em 100% de mortalidade, também com lesões hepáticas. Aspectos do cultivo, a importância da doença, as espécies de aves susceptíveis e seu papel na epidemiologia são discutidos. Abstract in english Since 2000, Macrorhabdus ornithogaster "megabacteriosis" has been diagnosed in the avian diseases laboratory in a diversity of avian species and varied spectrum of disease. The disease in some species (chickens, turkeys, guinea fowls) was clinically characterized by emaciation, prostration, loss of [...] appetite, cachexia and death, with a typically chronic course. A more acute disease was observed in finches (canary-Serinus and zebra-Taeniopygia) and budgerigars (Melopsittacus undulatus). The large rod shaped organism, visible from 100 times magnification, with and without staining, could be detected in sick and also in reasonably normal individuals of some species, such as chickens, turkeys, quails and pigeons. In rheas (Rhea americana), ostriches (Struthio camelus), canaries, zebra-finches, guinea-fowl (Numida meleagris) and budgerigars. The disease was severe, causing to up to 100% mortality. The infection could be detected in some species along with other infectious or disease problems, such as endoparasites (helminths, coccidia) and ectoparasitism (order Mallophaga or/and order Acarina). The cultivation of M. ornithogaster was successfully achieved in solid and liquid media, originated from chickens (four isolates), guinea fowl (1 isolate), chuckar partridge (1 isolate) and canary (1 isolate). A very interesting finding at microscopy was motility of M. ornithogaster, as detected both in cultures obtained on agar for pathogenic fungi and passaged into thioglycolate broth, as well as on samples observed in wet preparations from in vivo. Differences in colony aspects were noted among the isolates. Experimental infections were attempted in chicken and japanese quail, using a chicken isolate, allowing the detection of the organism in the proventriculus and liver in apparently normal birds. One chicken isolate was injected intraperitoneally in Balb/c mice and resulted in 100% mortality.

N.R.S., Martins; A.C., Horta; A.M., Siqueira; S.Q., Lopes; J.S., Resende; M.A., Jorge; R.A., Assis; N.E., Martins; A.A., Fernandes; P.R., Barrios; T.J.R., Costa; L.M.C., Guimarães.

280

Macrorhabdus ornithogaster in ostrich, rhea, canary, zebra finch, free range chicken, turkey, guinea-fowl, columbina pigeon, toucan, chuckar partridge and experimental infection in chicken, japanese quail and mice / Macrorhabdus ornithogaster em avestruzes, ema, canário, mandarim, galinha, peru, galinha da Angola, pombo doméstico, rolinha, tucano, perdiz de chuckar e infecção experimental em galinha, codorna e camundongo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Desde 2000, diversos casos de infecção e doença por Macrorhabdus ornithogaster (megabacteria) foram diagnosticados no Setor de Doenças das Aves (Escola de Veterinária da UFMG). A doença clínica foi caracterizada por emagrecimento, prostração, perda do apetite, caquexia e morte, em curso crônico, emb [...] ora com forma mais aguda em canários e periquitos. O microrganismo grande, em forma de bastão, visível a partir de 100 aumentos sem e com coloração, pode também ser detectado em aves de aspecto clínico normal, principalmente galinhas, perus, codornas e pombos. Em emas (Rhea), avestruzes (Struthio camelus), canários, mandarins, galinhas da Angola (Numida meleagris) e periquitos Australianos (Melopsittacus undulatus), a severidade da doença foi sempre maior, ocasionando até 100% de mortalidade em alguns plantéis. Na maioria das espécies a doença foi detectada em aves com endo e/ou ectoparasitismo. O cultivo de M. ornithogaster foi obtido em meio sólido (ágar para fungos patogênicos) e subcultivado em meio líquido (thioglicolato), do proventriculo de galinha, galinha da Angola, perdiz de chuckar e canário. O resultado mais surpreendente na microscopia de M. ornithogaster foi a presença de motilidade, detectada tanto de cultivos in vitro quanto de preparações úmidas de in vivo. Diferenças nos aspectos das colônias foram notadas entre os isolados. Infecções experimentais em galinha (SPF) e codorna japonesa permitiram a detecção do organismo nos proventrículos das aves de aspecto normal. Nas codornas, à necropsia notaram-se hemorragias hepáticas. A infecção experimental em camundongos via intraperitoneal resultou em 100% de mortalidade, também com lesões hepáticas. Aspectos do cultivo, a importância da doença, as espécies de aves susceptíveis e seu papel na epidemiologia são discutidos. Abstract in english Since 2000, Macrorhabdus ornithogaster "megabacteriosis" has been diagnosed in the avian diseases laboratory in a diversity of avian species and varied spectrum of disease. The disease in some species (chickens, turkeys, guinea fowls) was clinically characterized by emaciation, prostration, loss of [...] appetite, cachexia and death, with a typically chronic course. A more acute disease was observed in finches (canary-Serinus and zebra-Taeniopygia) and budgerigars (Melopsittacus undulatus). The large rod shaped organism, visible from 100 times magnification, with and without staining, could be detected in sick and also in reasonably normal individuals of some species, such as chickens, turkeys, quails and pigeons. In rheas (Rhea americana), ostriches (Struthio camelus), canaries, zebra-finches, guinea-fowl (Numida meleagris) and budgerigars. The disease was severe, causing to up to 100% mortality. The infection could be detected in some species along with other infectious or disease problems, such as endoparasites (helminths, coccidia) and ectoparasitism (order Mallophaga or/and order Acarina). The cultivation of M. ornithogaster was successfully achieved in solid and liquid media, originated from chickens (four isolates), guinea fowl (1 isolate), chuckar partridge (1 isolate) and canary (1 isolate). A very interesting finding at microscopy was motility of M. ornithogaster, as detected both in cultures obtained on agar for pathogenic fungi and passaged into thioglycolate broth, as well as on samples observed in wet preparations from in vivo. Differences in colony aspects were noted among the isolates. Experimental infections were attempted in chicken and japanese quail, using a chicken isolate, allowing the detection of the organism in the proventriculus and liver in apparently normal birds. One chicken isolate was injected intraperitoneally in Balb/c mice and resulted in 100% mortality.

N.R.S., Martins; A.C., Horta; A.M., Siqueira; S.Q., Lopes; J.S., Resende; M.A., Jorge; R.A., Assis; N.E., Martins; A.A., Fernandes; P.R., Barrios; T.J.R., Costa; L.M.C., Guimarães.

2006-06-01

 
 
 
 
281

Study of the biological effects of uranium exposure on zebra fish (D. rerio). Impact on life stages; Etude des effets biologiques de l'exposition a l'uranium chez le poisson zebre (D. rerio). Impact sur les stades de vie  

Energy Technology Data Exchange (ETDEWEB)

This work is part of an ongoing project (ENVIRHOM) started at IRSN in 2000, which consists in studying the environmental effects of radioactive substances at chronic low level of exposure. In this general frame, our aim was two fold: (i) to identify sensitivity of different critical life stages of zebra fish (fish of fresh water frequently used for tests standards in ecotoxicology) to uranium exposure and (ii) to evaluate underlying mechanisms. Experiments were conducted with eggs, larvae and genitors exposed to uranium at environmentally relevant concentrations (from 20 to 500 {mu}g/L) in order to study survival, hatching of eggs, growth of larvae and reproduction of genitors. Bio-markers of exposure (i.e. U bioaccumulation) and bio-markers of effects at molecular level (i.e. genotoxic effects, reproductive-toxicity) were also measured. Sensitivity of fish to uranium was dependent of the life stage of development with the early life stage being the most sensitive to U either directly or maternally exposed. It underlines the relevance of including pro-larval stages for toxicity assessments in fish. Moreover drastic effects of uranium on reproductive success and DNA damages in the germ cells foretell a strong impact on the population for low concentration of exposure (20 {mu}g/L). As it is increasingly recognized that population-level effects of toxic substances are more relevant in terms of ecological risk assessment, this study points out the need to include different life stages of organisms in eco-toxicological studies, especially the sensitive early stages. Moreover, it appears, through the comparative study of the radiological effects or by another isotope of the uranium of stronger radioactivity ({sup 233}U or by an irradiation with {sup 137}Cs), that the effects of the uranium are due to its chemo-toxicity. (author)

Bourrachot, St.

2009-05-15

282

78 FR 45954 - Endangered Species; Receipt of Applications for Permit  

Science.gov (United States)

...samples of Asian elephants (Elephas maximus) to the African Lion Safari, Ontario, Canada, for the purpose of enhancement...permit to export hair samples from captive bred Somali wild ass (Equus africanus somalicus) and Grevy's zebra...

2013-07-30

283

Mitochondrial Phylogenomics of Modern and Ancient Equids  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The genus Equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. To estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial sequences from all seven extant lineages within the genus Equus. Bayesian and Maximum Likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the Plains and Gr...

Vilstrup, Julia T.; Seguin-orlando, Andaine; Stiller, Mathias; Ginolhac, Aurelien; Raghavan, Maanasa; Nielsen, Sandra C. A.; Weinstock, Jacobo; Froese, Duane; Vasiliev, Sergei K.; Ovodov, Nikolai D.; Clary, Joel; Helgen, Kristofer M.; Fleischer, Robert C.; Cooper, Alan; Shapiro, Beth

2013-01-01

284

ORAL ESTROGEN MASCULINIZES FEMALE ZEBRA FINCH SONG SYSTEM. (R825294)  

Science.gov (United States)

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

285

Further bird records from the Bontebokand Mountain Zebra National Parks  

Directory of Open Access Journals (Sweden)

Full Text Available

The avifauna of this Park is well-known. Shortly after the Park was relocated to Swellendam in 1960, a preliminary list of the birds of the Park was published (Winterbottom 1962a. This was soon followed by a comprehensive check list (Winterbottom 1967a and a report on bird densities in the Coastal Renosterbosveld of the Park (Winterbottom 1968a. Six further bird species, five of which have been reported in The Ostrich, are documented here, increasing to 150 the total number of species recorded in the Park. The numbers denote those used in Roberts birds of South Africa (McLachlan and Liversidge 1970 and the nomenclature follows the Check list of the birds of South Africa (S.A.O.S. List Committee 1969.

B.L. Penzhorn

1977-08-01

286

Chronic fatigue syndrome: identifying zebras amongst the horses  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract There are currently no investigative tools or physical signs that can confirm or refute the presence of chronic fatigue syndrome (CFS. As a result, clinicians must decide how long to keep looking for alternative explanations for fatigue before settling on a diagnosis of CFS. Too little investigation risks serious or easily treatable causes of fatigue being overlooked, whilst too many increases the risk of iatrogenic harm and reduces the opportunity for early focused treatment. A paper by Jones et al published this month in BMC Medicine may help clinicians in deciding how to undertake such investigations. Their results suggest that if clinicians look for common psychiatric and medical conditions in those complaining of prolonged fatigue, the rate of detection will be higher than previously estimated. The most common co-morbid condition identified was depression, suggesting a simple mental state examination remains the most productive single investigation in any new person presenting with unexplained fatigue. Currently, most diagnostic criteria advice CFS should not be diagnosed when an active medical or psychiatric condition which may explain the fatigue is identified. We discuss a number of recent prospective studies that have provided valuable insights into the aetiology of chronic fatigue and describe a model for understanding chronic fatigue which may be equally relevant regardless of whether or not an apparent medical cause for fatigue can be identified. See the associated research paper by Jones et al: http://www.biomedcentral.com/1741-7015/7/57

Wessely Simon

2009-10-01

287

Long-Distance Retinoid Signaling in the Zebra Finch Brain  

Science.gov (United States)

All-trans retinoic acid (ATRA), the main active metabolite of vitamin A, is a powerful signaling molecule that regulates large-scale morphogenetic processes during vertebrate embryonic development, but is also involved post-natally in regulating neural plasticity and cognition. In songbirds, it plays an important role in the maturation of learned song. The distribution of the ATRA-synthesizing enzyme, zRalDH, and of ATRA receptors (RARs) have been described, but information on the distribution of other components of the retinoid signaling pathway is still lacking. To address this gap, we have determined the expression patterns of two obligatory RAR co-receptors, the retinoid X receptors (RXR) ? and ?, and of the three ATRA-degrading cytochromes CYP26A1, CYP26B1, and CYP26C1. We have also studied the distribution of zRalDH protein using immunohistochemistry, and generated a refined map of ATRA localization, using a modified reporter cell assay to examine entire brain sections. Our results show that (1) ATRA is more broadly distributed in the brain than previously predicted by the spatially restricted distribution of zRalDH transcripts. This could be due to long-range transport of zRalDH enzyme between different nuclei of the song system: Experimental lesions of putative zRalDH peptide source regions diminish ATRA-induced transcription in target regions. (2) Four telencephalic song nuclei express different and specific subsets of retinoid-related receptors and could be targets of retinoid regulation; in the case of the lateral magnocellular nucleus of the anterior nidopallium (lMAN), receptor expression is dynamically regulated in a circadian and age-dependent manner. (3) High-order auditory areas exhibit a complex distribution of transcripts representing ATRA synthesizing and degrading enzymes and could also be a target of retinoid signaling. Together, our survey across multiple connected song nuclei and auditory brain regions underscores the prominent role of retinoid signaling in modulating the circuitry that underlies the acquisition and production of learned vocalizations. PMID:25393898

Roeske, Tina C.; Scharff, Constance; Olson, Christopher R.; Nshdejan, Arpik; Mello, Claudio V.

2014-01-01

288

Leishmaniose tegumentar em uma mula (Equus caballus x equus asinus em área endêmica no Estado do Rio de Janeiro Cutaneous leishmaniasis in a mule (Equus caballus x Equus asinus in a endemic area of the state of Rio de Janeiro  

Directory of Open Access Journals (Sweden)

Full Text Available É relatado o encontro de infecção por parasitos do gênero Leishmania, em lesão cutânea de uma mula (Equus caballus x Equus asinus procedente de uma localidade endêmica de leishmaniose tegumentar, no Estado do Rio de Janeiro.Leishmania parasites were found in a skin lesion of a mule (Equus caballus x Equus asinus from a locality with endemic cutaneous leishmaniasis, in the state of Rio de Janeiro.

Cruz Manuel Aguilar

1986-06-01

289

Leishmaniose tegumentar em uma mula (Equus caballus x equus asinus) em área endêmica no Estado do Rio de Janeiro / Cutaneous leishmaniasis in a mule (Equus caballus x Equus asinus) in a endemic area of the state of Rio de Janeiro  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese É relatado o encontro de infecção por parasitos do gênero Leishmania, em lesão cutânea de uma mula (Equus caballus x Equus asinus) procedente de uma localidade endêmica de leishmaniose tegumentar, no Estado do Rio de Janeiro. [...] Abstract in english Leishmania parasites were found in a skin lesion of a mule (Equus caballus x Equus asinus) from a locality with endemic cutaneous leishmaniasis, in the state of Rio de Janeiro. [...

Cruz Manuel, Aguilar; Elizabeth F., Rangel.

290

Infecção natural de Equus caballus por Leishmania sp - São Paulo, Brasil (Breve comunicação científica) Natural infection of Equus caballus by Leishmania sp in São Paulo, Brazil, (Short communication)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

E assinalado, pela primeira vez, o encontro de um cavalo (Equus caballus) infeclado por Leishmania sp, no Estado de São Paulo.In São Paulo State a horse (Equus caballus) was found infected with Leishmania sp, for the first time.

Elizaide Luzia de Alvarenga Yoshida; Sílvio Alencar Marques; Hamilton Ometto Stolf; Luiz Antonio Barsotti; Márcia Maria Fattori Bueno; Roberto Sogayar

1988-01-01

291

Infecção natural de Equus caballus por Leishmania sp - São Paulo, Brasil (Breve comunicação científica Natural infection of Equus caballus by Leishmania sp in São Paulo, Brazil, (Short communication  

Directory of Open Access Journals (Sweden)

Full Text Available E assinalado, pela primeira vez, o encontro de um cavalo (Equus caballus infeclado por Leishmania sp, no Estado de São Paulo.In São Paulo State a horse (Equus caballus was found infected with Leishmania sp, for the first time.

Elizaide Luzia de Alvarenga Yoshida

1988-04-01

292

A Social Relations Model for the Colonial Behavior of the Zebra Finch  

Directory of Open Access Journals (Sweden)

Full Text Available A social relations model was developed for 5 years of behavioral recordings from a captive colony of Zebrafinches (Taeniopygia guttata. A quantitative ethogram was applied, using one-zero focal animal sampling on an ethologically comprehensive checklist of 52 behavioral items (Figueredo, Petrinovich, & Ross, 1992. Of the 9 ethological factors previously identified, only 4 of the 6 social factors (Social Proximity, Social Contact, Social Submission, and Social Aggression were used. Major results were as follows: (1 Individual finches showed systematically different response dispositions that were stable over a 5-year period as both subjects and objects of behavior; (2 Interactions between finches differed systematically by the sexes of both the subjects and the objects of behavior; (3 Behavioral interactions between finches and their mates differed systematically according to the subjects' sex, but also differed systematically from those with other members of the objects' sex; (4 Behavioral interactions between finches and their relatives differed systematically between different discrete categories of relatives, but did not vary as a systematic function of either graded genetic relatedness or familiarity due to common rearing; and (5 Behavioral interactions between finches and their relatives showed an overall bias towards preferential interactions with male relatives.

Vanya Alessandra Moreno

2010-01-01

293

Growth of a male Caracal kitten felis Caracal in the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available Three caracal (lynx Fells caracal kittens, two females and a male were received from the Fish River area some 50 km north of Cradock, Republic of South Africa, on the 20th March 1980. These were found at the base of a dense Rhus erosa bush on the side of a hill and estimated at 14 days old based on the findings of Cade (1968 Int. Zoo Yb. 45 and Kralik (1967 Int. Zoo Yb. 132.

J. H Grobler

1982-11-01

294

A re-assessment of the avifauna of the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available Based on all published records, together with the original data for the southern African bird atlas, the current Birds in Reserves Project and our records on field trips, 257 bird species have been reliably recorded from MZNP. We have assessed the current status of all species, in relation to the recent expansion of the park and other changes which may be a consequence of management practices. No birds of national conservation concern are breeding residents in the park, and some species are periodic or irregular visitors. Nevertheless, the park is important for the conservation of representatives of the Karoo avifauna, and the diversity of birdlife present should be highlighted to attract visitors with a special interest in birding.

P.E. Hilley

2005-06-01

295

Of spiders and zebras: publication of inadequately documented loxoscelism case reports.  

Science.gov (United States)

The dermatology and general medical literature is filled with articles that report skin disease caused by the brown recluse spider, Loxosceles reclusa. A large number of these articles contain inadequate documentation of Loxosceles bites; many come from areas that have no Loxosceles spiders. Authors submitting papers alleging loxoscelism should adhere to standards of evidence when writing case reports. PMID:17504721

Vetter, Richard S; Swanson, David L

2007-06-01

296

A re-assessment of the avifauna of the Mountain Zebra National Park  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on all published records, together with the original data for the southern African bird atlas, the current Birds in Reserves Project and our records on field trips, 257 bird species have been reliably recorded from MZNP. We have assessed the current status of all species, in relation to the recent expansion of the park and other changes which may be a consequence of management practices. No birds of national conservation concern are breeding residents in the park, and some species are p...

Hilley, P. E.; Craig, A. J. F. K.; Parker, D.

2005-01-01

297

Toxico-kinetic, chemical and radiological toxicity of uranium on zebra fish (Danio rerio)  

International Nuclear Information System (INIS)

This thesis explores the toxico-kinetic and toxicological aspects of uranium in fish. Uranium, appears to be highly bio accumulated and bio concentrated in fish. It spreads all through the whole organism. Nevertheless, its distribution is heterogeneous (gills and liver being the main sites of accumulation).From a toxicological point of view, we notice perturbations of the antioxidant system (inhibitions of hepatic Sod, Cat and G Px activities; depletion of total GSH) and of the cholinergic system (inhibition/over-activation of brain AChE). Genotoxic effects also appear in red blood cells, hepatocytes and gonad cells. The kinetics of these biochemical perturbations depend on the radiological activity of uranium, responses appearing earlier with increasing delivered activity. Histological effects (differing in types depending on delivered radiological activity) are also observed (in gills and muscles). (author)

298

Measurement and analysis of reaction rates in radial breeder regions of Zebra Assembly 13  

International Nuclear Information System (INIS)

Foil activation techniques have been used to study the major contributions of the power output from the radial breeder region of an operating mock-up of the Prototype Fast Reactor. Three breeder configurations have been investigated; a clean uranium-oxide breeder, an irradiated uranium-oxide breeder, and a uranium-carbide breeder. Predictions of the power distributions have been made using FGL5 data with both diffusion and transport theory models. It has been shown that the standard diffusion theory treatment may lead to errors of about 10% in breeder power relative to that in the core but that significant improvements are obtained by the use of transport theory. (author)

299

Estimation of costs of zebra mussel invasion in the Ebro basin (2005-2009 period)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Este estudio presenta los costes monetarios que ha supuesto la invasión del mejillón cebra en la cuenca del Ebro desde el año 2005 al 2009 para los sectores que utilizan el agua en sus actividades. El impacto económico asociado a esta invasión se deriva tanto de los problemas de funcionamiento de las instalaciones afectadas como de los gastos añadidos por la limpieza y tratamientos de control de las mismas. La metodología de trabajo se basó en el análisis de una encuesta dir...

Dura?n, Concha; Lanao, Munia; Pe?rez Y Pe?rez, Luis; Chica, Carlos; Anado?n, Antonia; Touya, Vicent

2012-01-01

300

A note on the smaller mammals of the Mountain Zebra National Park  

Directory of Open Access Journals (Sweden)

Full Text Available Collecting in April 1971 yielded 74 specimens of 16 species. Of these, seven species (Elephantulus rupestris, Lepus saxatilis, Pronolagus crassicaudatus, Graphiurus murinus, Aethomys namaquensis, Desmodillus auricularis and Gerbillurus paeba are new records for the park. Distribution in habitat-types for each species known to occur are described.

J. J. L. Pretorius

1971-05-01

 
 
 
 
301

Hydroxychloroquine-induced phospholipidosis in a case of SLE: the wolf in zebra clothing.  

Science.gov (United States)

A 30 year old lady patient of SLE on steroid and hydroxychloroquine therapy presented with lupus nephritis and later developed cardiac symptoms. Her renal biopsy revealed features of Class III lupus nephritis. Also seen was typical lamellated myelinoid material in the glomerulus. The alpha-galactosidase A activity was normal. The clinical morphological and biochemical findings were consistent with Lupus nephritis showing changes of hydroxychloroquine induced phopholipidosis. Electron microscopy along with careful clinical examination and follow up status was instrumental in the diagnosis of the latter. PMID:23573895

Khubchandani, Shaila Raju; Bichle, Lata Sunil

2013-04-01

302

Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175°C  

Energy Technology Data Exchange (ETDEWEB)

Operation of the sodium-nickel chloride battery at temperatures below 200°C reduces cell degradation and improves cyclability. One of the main technical issues with operating this battery at intermediate temperatures such as 175°C is the poor wettability of molten sodium on ?”-alumina solid electrolyte (BASE), which causes reduced active area and limits charging. In order to overcome the poor wettability of molten sodium on BASE at 175°C, a Pt grid was applied on the anode side of the BASE using a screen printing technique. Cells with their active area increased by metallized BASEs exhibited deeper charging and stable cycling behavior.

Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.

2014-01-01

303

Experiments with hydrogen-moderated control rods in ZEBRA assembly 14  

International Nuclear Information System (INIS)

Zero-power studies of the performance of fast reactor control rods containing both absorber and hydrogenous moderator are described. The absorbers included boron, europium and gadolinium, the moderator being simulated by polypropylene. Reactivity worths significantly greater than those of conventional designs were achieved, the most promising arrangement comprising a boron-carbide annulus enclosing a moderating central region. No evidence for local power peaking was observed for such annular geometries. (author)

304

Organophosphates in the Zebra Mussel Dreissena polymorpha : Subacute Exposure, Body Burdens, and Organ Concentrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Subacute exposures (10 d) of the freshwater mollusc Dreissena polymorpha to disulfoton (10 mg/L), thiometon (6 mg/L), and its activated oxygen analogue demeton-S-methyl (6 mg/L) corroborate earlier findings of organophosphate resistance and accumulation in the organism. Mortality occurred not before the ninth day of exposure. Mortality was induced at high ambient water concentrations and must be due to unknown specific organophosphate effects. Body burdens reached saturation levels within one...

Dauberschmidt, Carole; Dietrich, Daniel R.; Schlatter, Christian

1997-01-01

305

Toxicity of Organophosphorus Insecticides in the Zebra Mussel, Dreissena polymorpha P.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The 96-h toxicity of four organophosphates (thiometon, disulfoton, malathion, and demeton-S-methyl, the oxygen analogue of thiometon) in the freshwater bivalve mollusc Dreissena polymorpha was tested using different nominal concentrations ranging between 6 and 50 mg/L. No mortalities were observed in mussels exposed to malathion and demeton-S-methyl (26 mg/L and 6 mg/L, respectively), and at the lowest concentrations of thiometon and disulfoton (6 and 10 mg/L, respectively). At higher thiomet...

Dauberschmidt, Carole; Dietrich, Daniel R.; Schlatter, Christian

1996-01-01

306

Esterases in the zebra mussel Dreissena polymorpha : activities, inhibition, and binding to organophosphates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cholinesterase activities of Dreissena polymorpha were measured colorimetrically. In homogenates of whole control mussel, activities of 125 ± 29 ?mol min -1 kg -1 were found (n = 6). Neither after exposure of Dreissena to organophosphates (thiometon, disulfoton, demeton-S-methyl) nor after addition of demeton-S-methyl (the activated oxygen analogue of thiometon) in vitro was the measured mussel esterase activity inhibited. Esterases of rat, mouse and human tissue showed a 90 100% inhibition...

Dauberschmidt, Carole; Dietrich, Daniel R.; Schlatter, Christian

1997-01-01

307

Tallinnas Narva mnt. 7 asuva kohviku Zebra sisekujundus / Tiiu Truus, Tiiu Prisko, Mati Veermets...[jt.  

Index Scriptorium Estoniae

põhiplaan, 11 värv. vaadet; fotod: Kalle Veesaar; laes olevate dekoratiivsete lippude graafiline kujundus on Tiiu Priskolt ja Mati Veermetsalt, tualettruumi looduskivist valamu ja põrandavaasi autor on Kaido Kivi

2006-01-01

308

Uterine adenocarcinoma in a Przewalski's wild horse (Equus ferus przewalskii).  

Science.gov (United States)

A 25-yr-old, nulliparous, female Przewalski's wild horse (Equus ferus przewalskii) with a history of pituitary pars intermedia dysfunction and recent onset of serosanguinous vaginal discharge was euthanized after a period of lethargy and inappetance. Postmortem examination confirmed an infiltrative uterine adenocarcinoma, which is an uncommon neoplasia in equids. Reproductive disease is significant in this species as they are considered endangered by IUCN. Reproductive soundness and success are paramount to conservation efforts. PMID:25000717

Thompson, Rachel; Armién, Aníbal G; Rasmussen, James M; Wolf, Tiffany M

2014-06-01

309

Mitochondrial phylogenomics of modern and ancient equids  

DEFF Research Database (Denmark)

The genus Equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. To estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial sequences from all seven extant lineages within the genus Equus. Bayesian and Maximum Likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the Plains and Grevy's zebras form a well-supported monophyletic group. Using ancient DNA techniques, we further characterize the complete mitochondrial genomes of three extinct equid lineages (the New World stilt-legged horses, NWSLH; the subgenus Sussemionus; and the Quagga, Equus quagga quagga). Comparisons with extant taxa confirm the NWSLH as being part of the caballines, and the Quagga and Plains zebras as being conspecific. However, the evolutionary relationships among the non-caballine lineages, including the now-extinct subgenus Sussemionus, remain unresolved, most likely due to extremely rapid radiation within this group. The closest living outgroups (rhinos and tapirs) were found to be too phylogenetically distant to calibrate reliable molecular clocks. Additional mitochondrial genome sequence data, including radiocarbon dated ancient equids, will be required before revisiting the exact timing of the lineage radiation leading up to modern equids, which for now were found to have possibly shared a common ancestor as far as up to 4 Million years ago (Mya).

Vilstrup, Julia T; Seguin-Orlando, Andaine

2013-01-01

310

Infecção natural de Equus asinus por Leishmania braziliensis braziliensis - Bahia, Brasil Natural infection of Equus asinus by Leishmania braziliensis braziliensis - Bahia, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Em Corte de Pedra, Valença, Bahia, foi encontrado um jumento (Equus asinus, com infecção natural por Leishmania braziliensis braziliensis. O parasito foi isolado de uma lesão localizada na cicatriz da castração e identificado através de anticorpos monoclonais.In Corte de Pedra, Valença, state of Bahia, a donkey, Equus asinus, was found naturally infected with Leishmania braziliensis braziliensis. The parasite was isolated from a lesion located on a castration scar, and identified by means of monoclonal antibodies.

Julio A. Vexenat

1986-06-01

311

Research on Donkey Populations (Equus Asinus in Banat  

Directory of Open Access Journals (Sweden)

Full Text Available Research has been made in what concerns the bodily development of donkeys (Equus asinus in Banat, on a number of 94 specimens. The results have shown a great variety in body measures, colours and hues. The Banat Donkey comes from different areas in Romania, Europe or Levant. In 2010 in Banat there were approx. 1000 donkey specimens, 98% of which pertained to shepherds. In the case of this species the mating occurs naturally, and a selection has never been made. Their meat and milk are only rarely consumed by some communities, even if their milk is highly appreciated in the European Union.

Marcel Matiuti

2011-05-01

312

Esteatosis en un burro (Equus asinus). Primer reporte en Colombia / Steatosis in donkey (Equus asinus). First report in Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Se describe un caso de esteatosis en un burro (Equus asinus), castrado, de 15 años de edad, procedente del municipio de San Antero (Córdoba, Colombia), al cual se le detectó ligamento nucal engrosado, duro y doloroso, dando la impresión de un doble cuello y edemas subcutáneos indurados en pared cost [...] al, abdominal y pectoral. También presentó masas duras en la unión de músculos semimembranoso y semitendinoso. Por todo lo anterior, mostró dificultad para realizar movimientos coordinados del cuello, nuca y de traslado. Estos hallazgos obedecen principalmente a una deficiencia de selenio y vitamina E, sirviendo como parámetro diagnóstico para la identificación de esta enfermedad en equinos, por lo cual se determinó la actividad eritrocitica de la enzima glutatión peroxidada (GSH-Px), arrojando resultados muy bajos. Este cuadro es también conocido en equinos como enfermedad de la grasa amarilla o esteatitis, que produce degeneración del tejido adiposo, siendo reemplazado por tejido conectivo con depósitos de calcio. Puede estar asociada a miodegeneración nutricional o distrófica (enfermedad del músculo blanco). Es el primer reporte de esta enfermedad en burros (Equus asinus) que se hace en Colombia. Abstract in english A case of steatosis in a, 15 years old gelding donkey (Equus asinus), from the town of San Antero (Cordoba, Colombia) is described. the donkey, showed a hard and painful thickened nuchal ligament, giving the impression of a double neck tumors. It was also found an edema in the indurated subcutaneous [...] chest wall, abdomen and chest. It was also found hard lumps in the union of semimembranosus and semitendinosus muscles, which produced difficulty in the movility of the neck and coordinated translation. It is well known that this findings are due to a deficiency of selenium and vitamin E, giving them as diagnostic parameters for the presentation of this disease in horses, so we determined the enzyme activity of erythrocyte glutathione peroxidase (GSH-Px), yielding results very low. This condition is also known as yellow fat disease or steatitis in horses and produces degeneration of adipose tissue which is replaced by connective tissue and calcium deposits and may be associated with nutritional or dystrophic miodegeneration (white muscle disease). As far as we know this is the first report of steatosis in donkeys (Equus asinus) in Colombia.

José, Cardona; Lázaro, Reza G.

313

Esteatosis en un burro (Equus asinus). Primer reporte en Colombia / Steatosis in donkey (Equus asinus). First report in Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Se describe un caso de esteatosis en un burro (Equus asinus), castrado, de 15 años de edad, procedente del municipio de San Antero (Córdoba, Colombia), al cual se le detectó ligamento nucal engrosado, duro y doloroso, dando la impresión de un doble cuello y edemas subcutáneos indurados en pared cost [...] al, abdominal y pectoral. También presentó masas duras en la unión de músculos semimembranoso y semitendinoso. Por todo lo anterior, mostró dificultad para realizar movimientos coordinados del cuello, nuca y de traslado. Estos hallazgos obedecen principalmente a una deficiencia de selenio y vitamina E, sirviendo como parámetro diagnóstico para la identificación de esta enfermedad en equinos, por lo cual se determinó la actividad eritrocitica de la enzima glutatión peroxidada (GSH-Px), arrojando resultados muy bajos. Este cuadro es también conocido en equinos como enfermedad de la grasa amarilla o esteatitis, que produce degeneración del tejido adiposo, siendo reemplazado por tejido conectivo con depósitos de calcio. Puede estar asociada a miodegeneración nutricional o distrófica (enfermedad del músculo blanco). Es el primer reporte de esta enfermedad en burros (Equus asinus) que se hace en Colombia. Abstract in english A case of steatosis in a, 15 years old gelding donkey (Equus asinus), from the town of San Antero (Cordoba, Colombia) is described. the donkey, showed a hard and painful thickened nuchal ligament, giving the impression of a double neck tumors. It was also found an edema in the indurated subcutaneous [...] chest wall, abdomen and chest. It was also found hard lumps in the union of semimembranosus and semitendinosus muscles, which produced difficulty in the movility of the neck and coordinated translation. It is well known that this findings are due to a deficiency of selenium and vitamin E, giving them as diagnostic parameters for the presentation of this disease in horses, so we determined the enzyme activity of erythrocyte glutathione peroxidase (GSH-Px), yielding results very low. This condition is also known as yellow fat disease or steatitis in horses and produces degeneration of adipose tissue which is replaced by connective tissue and calcium deposits and may be associated with nutritional or dystrophic miodegeneration (white muscle disease). As far as we know this is the first report of steatosis in donkeys (Equus asinus) in Colombia.

José, Cardona; Lázaro, Reza G.

2793-27-01

314

Esteatosis en un burro (Equus asinus. Primer reporte en Colombia  

Directory of Open Access Journals (Sweden)

Full Text Available Se describe un caso de esteatosis en un burro (Equus asinus, castrado, de 15 años de edad, procedente del municipio de San Antero (Córdoba, Colombia, al cual se le detectó ligamento nucal engrosado, duro y doloroso, dando la impresión de un doble cuello y edemas subcutáneos indurados en pared costal, abdominal y pectoral. Tambiénpresentó masas duras en la unión de músculos semimembranoso y semitendinoso. Por todo lo anterior, mostró dificultad para realizar movimientos coordinados del cuello, nuca y de traslado. Estos hallazgos obedecen principalmente a una deficiencia de selenio y vitamina E, sirviendo como parámetro diagnóstico para la identificación de esta enfermedad en equinos, por lo cual se determinó la actividad eritrocitica de la enzima glutatión peroxidada (GSH-Px, arrojando resultados muy bajos. Este cuadro es también conocido en equinos como enfermedad de la grasa amarilla o esteatitis, que produce degeneración del tejido adiposo, siendo reemplazado por tejido conectivo con depósitos de calcio. Puede estar asociada a miodegeneración nutricional o distrófica (enfermedad del músculo blanco. Es el primer reporte de esta enfermedad en burros(Equus asinus que se hace en Colombia.

José Cardona Á.

2011-12-01

315

Nuevo registro de Equus (Amerhippus) santaeelenae (Mammalia, Perissodactyla) del pozo de asfalto de Inciarte (Pleistoceno Superior), estado Zulia, Venezuela / New record of Equus (Amerhippus) santaeelenae (Mammalia, Perissodactyla) from the Pozo de asfalto de Inciarte site (Late Pleistocene), Zulia State, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Los fósiles de Equidae del pozo de asfalto de Inciarte son descritos y determinados taxonómicamente. Se han comparado los p3-4 inferiores de Inciarte con los de Equus (Amerhippus) andium, Equus (A.) santaeelenae, Equus (A.) insulatus y Equus (A.) neogeus de varias localidades de América del Sur medi [...] ante análisis multivariante. Los resultados de este análisis indican que la especie Equus (Amerhippus) santaeelenae (Spillmann) está representada en el yacimiento. Se discuten sus implicaciones paleoecológicas. Algunos autores sugieren que un estrés nutricional, producto de un cambio rápido en las comunidades vegetales, podría ser una de las causas que expliquen la extinción de fines del Pleistoceno. La especialización en la dieta que se atribuye a esta especie es una evidencia en favor de esta teoría. Abstract in english Fossil remains of Equidae from the asphaltic well of Inciarte quarry are described and taxonomically determined. We compared the lower p3-4 from Inciarte with Equus (Amerhippus) andium, Equus (A.) santaeelenae, E. (A.) insulatus and Equus (A.) neogeus remains from several localities in South America [...] using multivariate analysis. The results of this analysis indicate that Equus (Amerhippus) santaeelenae (Spillmann) is represented in the quarry. Its paleoecological implications are discussed. The resource partitioning preference of this species supports the several nutritional hypotheses to explain latest Pleistocene extinctions.

Ascanio D., Rincón R.; María Teresa, Alberdi; José Luis, Prado.

316

Pleistocene horses (genus Equus in the central Balkans  

Directory of Open Access Journals (Sweden)

Full Text Available A review of the fossil horses of the genus Equus from the central Balkans, a mountainous area comprising Serbia and Montenegro, is presented in this paper. The time period covered by the finds is from the late Early to and including the Late Pleistocene, but the record is not complete: the dated finds are Late Pleistocene in age, while Early and Middle Pleistocene are poorly represented. The horses found resemble those from neighbouring countries from the same time period, probably showing the importance of river valleys as migration routes. The Morava River valley runs in a roughly south-to-north direction, connecting, via the Danube and Tisa River valleys the Hungarian Pannonian Plain in the north with northern Greece in the south, via the Vardar River valley in Macedonia. In Pleistocene, large mammals, including horses, probably used this route for dispersal.

Forsten Ann

2003-01-01

317

Research and Development (R&D) Series 06/25 - Management of the Impacts of Zebra Mussels in ...  

...Lane, Belfast BT9 5PX. 3 School of Biology and Biochemistry, Queens University of Belfast, Medical...and Biochemistry, Queens University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast. II Executive...

318

Short communication. Evaluation of presumptive caudal fin blastema cells as candidate donors in intra species zebra fish (Danio rerio) chimaeras  

Energy Technology Data Exchange (ETDEWEB)

The blastema is a regenerative tissue with remarkable pluripotency. The aim of this work done on zebrafish (Danio rerio) was to define technical procedures required for obtaining and integrating blastema cells into embryos at the mid blastula transition stage (MBT) and the effect on survival, as well as the capacity to produce pigmented chimaeras. Wild type blastema cells were injected into gold type MBT embryos (E). Wild MBT blastomere cells were also injected into gold type MBT embryos as a control (C{sub 1}). A second control group, C{sub 2}, was not subjected to any manipulation. Survival was evaluated at 24, 48 and 72 h after performing the chimaerism, and the rate of adult chimaeras evaluated. The results showed significant differences in embryo survival between the E and C{sub 1} groups in embryo survival at 24 and 48 h postchimaerism (24 h: E-83.49% vs C{sub 1}-54.8%, p < 0.05; 48 h: E-98.83% vs C{sub 1}-85.13%, p < 0.05). There was no significant difference, at any time, between E and C{sub 2}. The results at 72 h for E and the controls (E-89.41%; C{sub 1}-84.12% and C{sub 2}-92.55%) indicate that insertion of blastema cells does not have a negative effect on embryo development. The results in adults (E: 0 chimaeras from 7 specimens; C{sub 1}: 5 chimaeras from 17 specimens) suggest that the dedifferentiation grade of the blastema cells may not be enough to generate germ-line chimaeras, but their condition of potentially dedifferentiating cells may be an advantage when using them as donor nuclei in somatic cloning by nuclear transplant. Additional key words: biodiversity, chimaerism, embryo, zebrafish. (Author) 19 refs.

Perez-Camps, M.; Francisco Simao, M.; Cardona Costa, J.; Garcia-Ximenez, F.

2008-07-01

319

A Study of the Survival and Oxygen Deficiency at the Zebra Mussel (Dreissena polymorpha Treated with Zinc (Zn  

Directory of Open Access Journals (Sweden)

Full Text Available The current paper studies the change of respiratory rate and survival of Dreissena polymorpha at short exposure to zinc under laboratory conditions. The experiment is lasted 96h and three different concentrations of ZnSO4.7H2O were used - 0.5mg/l, 1.5mg/l; 2,0 mg/l. Survival and intensity of breathing of Dreissena polymorpha decreases with the increasing concentration of zinc in the water.

Bogdan N. Nikolov

2009-07-01

320

Sometimes when you hear hoof beats, it could be a zebra: consider the diagnosis of Fabry disease  

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Full Text Available Abstract Background Fabry disease is an X-linked lysosomal storage disorder that results from a deficiency of the enzyme ?-galactosidase A. Fabry disease is present in 4–5% of men with unexplained left ventricular hypertrophy or cryptogenic stroke. As enzyme replacement therapy is now more widely available, it is important to recognise the signs and symptoms of the disease and establish the diagnosis so that early treatment can be started before irreversible organ damage occurs. Case Presentation A previously fit and well 32-year-old Caucasian male presented with multisystem dysfunction including renal impairment. Although he had no suggestive symptoms, a diagnosis of Fabry disease was first established on a native renal biopsy. This was confirmed by enzymatic testing and subsequent genetic analysis that revealed a potentially new pathogenic variant. Conclusions This case highlights the importance both of Fabry disease as a differential diagnosis in patients with renal impairment in the context of multi-system disease and also of adequate tissue sampling for electron microscopy when performing native renal biopsies.

Burton James O

2012-07-01

 
 
 
 
321

Low environmental levels of fluoxetine induce spawning and changes in endogenous estradiol levels in the zebra mussel Dreissena polymorpha  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pharmaceutical fluoxetine, a selective serotonin reuptake inhibitor (SSRI), is often detected in municipal wastewater treatment plant effluents and surface waters within the ng/l range. There is, however, insufficient research evaluating potential hazards of fluoxetine in aquatic organisms at environmentally relevant concentrations. Taking into account that several SSRIs (fluoxetine, fluvoxamine) act as spawning inducers in bivalves, this study aimed at investigating the effects of fluoxe...

Lazzara, Raimondo; Bla?zquez, Mercedes; Porte Visa, Cinta; Barata Marti?, Carlos

2012-01-01

322

Odour-based natal nest recognition in the zebra finch (Taeniopygia guttata), a colony-breeding songbird  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Passerine birds have an extensive repertoire of olfactory receptor genes. However, the circumstances in which passerine birds use olfactory signals are poorly understood. The aim of this study is to investigate whether olfactory cues play a role in natal nest recognition in fledged juvenile passerines. The natal nest provides fledglings with a safe place for sleeping and parental food provisioning. There is a particular demand in colony-breeding birds for fledglings to be able to identify the...

Caspers, Barbara A.; Krause, E. Tobias

2011-01-01

323

Uptake and elimination of (9-/sup 14/C)phenanthrene in the turkey wing mussel (Arca zebra)  

Energy Technology Data Exchange (ETDEWEB)

Turkey wing mussels of both sexes were collected from Harrington Sound, Bermuda and dosed after a week-long acclimation period with (9-/sup 14/C)phenanthrene (714 MBq/mmol). They were transferred into 8 liters of seawater containing 8 ..mu..g of labelled phenanthrene. Results show that the accumulation of labelled phenanthrene in the turkey wing mussel was very low compared to that found in other species. In the hepatopancreas, the uptake of phenanthrene based on the water concentration was only 4% of the corresponding value found in the calico clam (Macrocallista maculata) inhabiting the same area. In comparison, the uptake of phenanthrene in a temperate mollusc such as the horse mussel (Modiola modiolus) was also considerably higher than in the turkey wing (approx. 4 times). It therefore seems likely that these are due to species variations rather than environmental variations between subtropical and temperate areas. (JMT)

Solbakken, J.E. (Inst. of Marine Research, Bergen, Norway); Knap, A.H.; Searle, C.E.; Palmork, K.H.

1983-04-01

324

Long-term stability of grazing lawns in a small protected area, the Mountain Zebra National Park  

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Full Text Available We examined a heavily grazed plant community dominated by creeping grass species with the aim of, (1 determining its response to the exclusion of grazing and (2 its long-term persistence. This plant community was particularly favoured by wild ungulate species that prefer short grasses – blesbok (Damaliscus dorcas phillipsi, springbok (Antidorcas marsupialis and black wildebeest (Connochaetes gnou. Exclusion of grazing by large herbivores by means of fencing resulted in the virtual disappearance of the creeping grasses and their replacement by tall tufted species. On plots that remained unfenced, the plant species composition was found to be little changed after an interval of more than 20 years. The number large stock unit equivalents (LSU per ha carried by the plant community was used as a proxy for grazing intensity. Monitored for approximately 2 years at the start of the study, LSU per ha was found to greatly exceed levels recommended for commercial livestock production. This plant community conforms to a recently published definition of a grazing lawn, in that intense grazing promotes palatable, grazing-tolerant grass species. Conservation implications: The positive association between grazers and grazing-tolerant grass species evidently persisted for more than 20 years and there was no evidence of an increase in abundance of unpalatable plant species. Despite the small size of the park, which limited the extent of large herbivore movements, localised heavy grazing did not lead to range degradation.

Peter Novellie

2013-08-01

325

High-dose oral ziprasidone versus conventional dosing in schizophrenia patients with residual symptoms: the ZEBRAS study.  

Science.gov (United States)

Uncontrolled studies have suggested that increasing the dose of ziprasidone above the standard maximum daily dose of 160 mg may be more effective for some patients with schizophrenia. To test this hypothesis, we conducted an 8-week, placebo-controlled, fixed-dose escalation trial comparing ziprasidone 160 versus 320 mg/d in individuals with schizophrenia or schizoaffective disorder who remained symptomatic despite treatment with ziprasidone 160 mg/d for at least 3 weeks. Of 75 randomized patients, 42 completed the study. Serum ziprasidone concentrations increased significantly in the high-dose group compared with the standard-dose group at week 4 but did not differ between groups at week 8. Both treatment groups exhibited significant symptomatic improvement. Response did not differ between treatment groups; however, in the high-dose group, higher ziprasidone serum concentrations were associated with better response at a trend level. Higher ziprasidone concentrations were also associated with reductions in diastolic blood pressure and, at a trend level, with more prominent negative symptoms and greater QTc prolongation. In summary, increasing the ziprasidone dose to 320 mg/d did not produce a sustained elevation in serum concentrations or symptomatic improvement compared with a standard ziprasidone dose of 160 mg/d. PMID:23775057

Goff, Donald C; McEvoy, Joseph P; Citrome, Leslie; Mech, Arnold W; Bustillo, Juan R; Gil, Roberto; Buckley, Peter; Manschreck, Theo C; Achtyes, Eric D; Macklin, Eric A

2013-08-01

326

Learning of Monotonic and Nonmonotonic Sequences in Domesticated Horses ("Equus Callabus") and Chickens ("Gallus Domesticus")  

Science.gov (United States)

(Hulse and Dorsky, 1977) and (Hulse and Dorsky, 1979) found that rats, like humans, learn sequences following a simple rule-based structure more quickly than those lacking a rule-based structure. Through two experiments, we explored whether two additional species--domesticated horses ("Equus callabus") and chickens ("Gallus domesticus")--would…

Kundey, Shannon M. A.; Strandell, Brittany; Mathis, Heather; Rowan, James D.

2010-01-01

327

Population viability analysis on domestic horse breeds (Equus caballus)  

DEFF Research Database (Denmark)

In this study, we performed a population viability analysis on 3 domestic horse breeds (Equus caballus) of Danish origin, namely, the Frederiksborg, the Knabstrupper, and the Jutland breeds. Because of their small population sizes, these breeds are considered endangered. The Vortex software simulation package was used for the population viability analysis. First, we investigated the future viability of these breeds based on present demographic and environmental parameters. Second, a sensitivity analysis revealed the most important variables for the viability of these breeds. Third, we examined management scenarios in which one of the studbooks was closed. According to the Vortex analysis, 2 of the breeds (Knabstrupper and Jutland) will persist for the next 200 yr, whereas the smaller breed (Frederiksborg) could become extinct within 40 yr. The sensitivity analyses indicated that the variables concerning reproduction of the mares had the greatest impact, with the number of mares actively breeding being the most influential on the population forecasts. The results suggest that closing the Knabstrupper studbooks can be done only if increasing the number of mares actively breeding counteracts the loss of genetic variation attributable to such a management strategy. It is recommended, based on these results, that the number of Frederiksborg and Knabstrupper mares actively breeding must be increased to approximately 30% in the 2 breeds that are presently using only 13%, while leaving the third (Frederiksborg ) at its present 30% level. Monitoring of the breeds in the future, however, may be exploited to adjust the breeding strategies. We suggest that the large amount of data required by Vortex makes it very useful for analyzing domestic animals because of the comprehensive data material often available. The results of this analysis accord with other studies on the Prezwalski horse, indicating robustness in the parameter sensitivity for horses.

Thirstrup, Janne Pia; Bach, Lars

2009-01-01

328

Horse (Equus caballus) whinnies: a source of social information.  

Science.gov (United States)

Many animal species that rely mainly on calls to communicate produce individual acoustic structures, but we wondered whether individuals of species better known as visual communicants, with small vocal repertoires, would also exhibit individual distinctiveness in calls. Moreover, theoretical advances concerning the evolution of social intelligence are usually based on primate species data, but relatively little is known about the social cognitive capacities of non-primate mammals. However, some non-primate species demonstrate auditory recognition of social categories and possess mental representation of their social network. Horses (Equus caballus) form stable social networks and although they display a large range of visual signals, they also use long-distance whinny calls to maintain contact. Here, we investigated the potential existence of individual acoustic signatures in whinny calls and the ability of horses to discriminate by ear individuals varying in their degree of familiarity. Our analysis of the acoustic structure of whinnies of 30 adult domestic horses (ten stallions, ten geldings, ten mares) revealed that some of the frequency and temporal parameters carried reliable information about the caller's sex, body size and identity. However, no correlations with age were found. Playback experiments evaluated the behavioural significance of this variability. Twelve horses heard either control white noise or whinnies emitted by group members, familiar neighbours or unfamiliar horses. While control sounds did not induce any particular response, horses discriminated the social category of the callers and reacted with a sound-specific behaviour (vigilance and attraction varied with familiarity). Our results support the existence of social knowledge in horses and suggest a process of vocal coding/decoding of information. PMID:19449192

Lemasson, Alban; Boutin, Anaïs; Boivin, Sarah; Blois-Heulin, Catherine; Hausberger, Martine

2009-09-01

329

Identificación de Especímenes de Equus grevyi en el Parque Zoológico Nacional de Cuba  

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Full Text Available La cebra de Grevy (Equus grevyi se ha manejado a través de extracciones y reintroducciones de individuos desde su inclusión en la colección de animales del Parque Zoológico Nacional de Cuba. Para mejorar el manejo de esta especie es necesaria la identificación individual a través de caracteres morfológicos, por esto los que los investigadores se propusieron demostrar las diferencias en el patrón de rayado facial existente entre los individuos y entre ambos lados de un mismo individuo. El método de marcas naturales fue utilizado para la identificación de estos animales a través de fotografías. Las imágenes tomadas se compararon visualmente y se observó la diferencia existente en el patrón de rayado facial entre individuos y entre los lados faciales de un mismo individuo.Identification of Specimens in Equus grevyi in the Cuba National Zoo Park Abstract. Equus grevyi has managed through the extraction and the reintroduction of individuals from your entrance to the collection of animals of the Cuba National Zoo Park. To improve the handling of this species it is necessary the individual identification through morphological characters for those who proposed us demonstrate the differences in the owner of facial existent stripes between the individuals and between both patrons of a same individual. The outstanding method naturals were used for the identification of these animals through the photo. The taken images compared visual and it is observed the existent difference in the owner of facial stripes between individual and between the facial patrons of a same individual.

Irina Fermin-Morales

2014-07-01

330

Sequencing and expression analysis of hepcidin mRNA in donkey (Equus asinus) liver / Sequenciamento e expressão do RNA mensageiro da hepcidina no fígado de jumentos (Equus asinus)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A hipoferremia observada durante os processos inflamatórios sistêmicos é mediada pela hepcidina, um peptídeo que é sintetizado predominantemente no fígado de mamíferos. A hepcidina desempenha um papel chave no metabolismo do ferro e no sistema imune. O aumento da expressão da hepcidina é particularm [...] ente útil durante a inflamação aguda, pois restringe a disponibilidade de ferro, necessária para o crescimento de microorganismos patogênicos. Neste estudo, o RNA mensageiro da hepcidina asinina foi caracterizado e sua expressão foi determinada em fígado de jumentos (Equus asinus). A sequência da hepcidina asinina tem uma janela de leitura de 261 nucleotídeos e a proteína correspondente é formada por 86 aminoácidos. A sequência de aminoácidos da hepcidina asinina foi mais homóloga à sequência da hepcidina equina (98%). A hepcidina madura (25 aminoácidos) foi 100% idêntica à hepcidina madura equina e possuía as oito cisteínas conservadas nas demais sequências de hepcidinas analisadas. O perfil de expressão da hepcidina no fígado de jumentos saudáveis foi alto e similar ao perfil de expressão do gene de referência. A sequência da hepcidina asinina foi depositada no GenBankTM (HQ902884) e será útil para o desenvolvimento de estudos adicionais sobre o metabolismo de ferro e inflamação nesta espécie. Abstract in english The hypoferremia that is observed during systemic inflammatory processes is mediated by hepcidin, which is a peptide that is mainly synthesized in the livers of several mammalian species. Hepcidin plays a key role in iron metabolism and in the innate immune system. It's up-regulation is particularly [...] useful during acute inflammation, and it restricts the iron availability that is necessary for the growth of pathogenic microorganisms. In this study, the hepcidin mRNA of Equus asinus has been characterized, and the expression of donkey hepcidin in the liver has been determined. The donkey hepcidin sequence has an open reading frame (ORF) of 261 nucleotides, and the deduced corresponding protein sequence has 86 amino acids. The amino acid sequence of donkey hepcidin was most homologous to Equus caballus (98%). The mature donkey hepcidin sequence (25 amino acids) was 100% homologous to the equine mature hepcidin and has eight conserved cysteine residues that are found in all of the investigated hepcidin sequences. The expression profile of donkey hepcidin in the liver was high and was similar to the reference gene expression. The donkey hepcidin sequence was deposited in GenBankTM (HQ902884) and may be useful for additional studies on iron metabolism and the inflammatory process in this species.

José P., Oliveira-Filho; Jessica A., Marques; Paulo Henrique J., Cunha; Gildenor X., Medeiros; Franklin, Riet-Correa; Vânia Maria V., Machado; Alexandre S., Borges.

1050-10-01

331

Presencia de Hippidion y Equus (Amerhippus (Mammalia, Perissodactyla y su distribución en el Pleistoceno superior de Chile  

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Full Text Available Fossil remains belonging to Equidae fram Chilean localities are described and taxonomically determined. Equus (Amerhippus and Hippidion species are identified; its geographic distribution in Chile and relations with others South American Equidae are given; a Late Pleistocene age is regarded for them. Stratigraphic and paleoecological considerations are also included.Se describen y sitúan taxonómicamente los restos de équidos de las localidades chilenas. Se identifican distintas especies de Equus (Amerhippus e Hippidion, señalando su distribución geográfica y relaciones con otros équidos sudamericanos, además de referirlos al Pleistoceno superior. Se analiza su situación estratigráfica así como consideraciones de tipo paleoecológico.

Frassinetti, D.

2000-12-01

332

Inoculação experimental de Equus asinus com Leishmania chagasi Cunha & Chagas, 1937 / Experimental infection of Equus asinus with Leishmania chagasi Cunha & Chagas, 1937  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Quatro Equus asinus foram inoculados com promastigotas de Leishmania chagasi Cunha & Chagas, 1937 e acompanhados durante 12 meses através de: pesquisa de amastigotas em esfregaços e culturas de sangue periférico em fragmentos de tecido do lábio inferior, medula óssea, baço e fígado e de testes de EL [...] ISA e TRALd. Estes foram positivos nos 8º, 10º e 12º meses após a inoculação. O exame histopatológico pós necropsia, demonstrou discreto número de amastigotas no fígado de dois dos eqüídeos inoculados. Apesar de desafiados com elevado número de promastigotas, os animais não desenvolveram infecções patentes e não infectaram experimentalmente a vetora Lutzomya longipalpis. Os resultados induzem a acreditar que os eqüídeos são desprovidos de importância como reservatórios na cadeia de transmissão da leishmaniose visceral, embora sirvam como boa fonte de alimentação sangüínea e proliferação da vetora Lutzomyia longipalpis. Abstract in english Four Equus asinus were challenged with promastigotes of Leishmania chagasi Cunha & Chagas, 1937, and followed up for 12 months. They were observed by means of direct testing for promastigotes in smears and culture of peripheral blood, fragments from inferior lip, bone marrow, spleen and liver and th [...] e immunological assays ELISA and TRALd. The post-necropsy histological examination demonstrated a small number of amastigotes in the liver of two animals. ELISA and TRALd tests were positive at the 8th, 10th and 12th month after inoculation. The results suggest that the donkeys were able to overcome the experimental leishmanial infection and did not infect the vector Lutzomyia longipalpis in the laboratory. Consequently they can not be considered an important reservoir in the epidemiological chain of transmission of visceral leishmaniasis, although they represent an important blood source for the vector and its proliferation.

Elúzio José Lima, Cerqueira; Italo, Sherlock; Alberto, Gusmão; Aryon de Almeida, Barbosa Junior; Maria, Nakatani.

333

Inoculação experimental de Equus asinus com Leishmania chagasi Cunha & Chagas, 1937 Experimental infection of Equus asinus with Leishmania chagasi Cunha & Chagas, 1937  

Directory of Open Access Journals (Sweden)

Full Text Available Quatro Equus asinus foram inoculados com promastigotas de Leishmania chagasi Cunha & Chagas, 1937 e acompanhados durante 12 meses através de: pesquisa de amastigotas em esfregaços e culturas de sangue periférico em fragmentos de tecido do lábio inferior, medula óssea, baço e fígado e de testes de ELISA e TRALd. Estes foram positivos nos 8º, 10º e 12º meses após a inoculação. O exame histopatológico pós necropsia, demonstrou discreto número de amastigotas no fígado de dois dos eqüídeos inoculados. Apesar de desafiados com elevado número de promastigotas, os animais não desenvolveram infecções patentes e não infectaram experimentalmente a vetora Lutzomya longipalpis. Os resultados induzem a acreditar que os eqüídeos são desprovidos de importância como reservatórios na cadeia de transmissão da leishmaniose visceral, embora sirvam como boa fonte de alimentação sangüínea e proliferação da vetora Lutzomyia longipalpis.Four Equus asinus were challenged with promastigotes of Leishmania chagasi Cunha & Chagas, 1937, and followed up for 12 months. They were observed by means of direct testing for promastigotes in smears and culture of peripheral blood, fragments from inferior lip, bone marrow, spleen and liver and the immunological assays ELISA and TRALd. The post-necropsy histological examination demonstrated a small number of amastigotes in the liver of two animals. ELISA and TRALd tests were positive at the 8th, 10th and 12th month after inoculation. The results suggest that the donkeys were able to overcome the experimental leishmanial infection and did not infect the vector Lutzomyia longipalpis in the laboratory. Consequently they can not be considered an important reservoir in the epidemiological chain of transmission of visceral leishmaniasis, although they represent an important blood source for the vector and its proliferation.

Elúzio José Lima Cerqueira

2003-12-01

334

"Pop" psychoanalysis, kitsch, and the "as if" theater: further notes on Peter Shaffer's Equus.  

Science.gov (United States)

This paper is intended as an examination of Dr. Stamm's (1975) paper and of Dr. Jules Glenn's discussion of Peter Shaffer's previous work. Its premise is the futility of subjecting Equus to a traditional psychoanalytic investigation, as a product of the playwright's unconscious, when the play represents a skillful, highly conscious use of analytic cliches to manipulate the audience. This phenomenon, however, and the play's great popularity prompt some reflections on the nature of kitsch, or false art, and its differences from authentic drama. The experience of kitsch can be identified when the spectator feels coerced by exaggerated, unconvincing theatrical devices, and fails to experience genuine empathy with the characters in a play. In the experience of authentic tragedy there is some element of voluntary surrender, of suspension of disbelief with full consent of will, as in the Aristotelian concept of catharsis. Shaffer's play is discussed as an illustration of this distinction and its relation to pseudoemotionality, the impostor syndrome, and the "as if" personality. In conclusion, the play's failure to evoke a genuine emotional response is explained by interpreting Equus as an "as if" tragedy. PMID:986375

Gifford, S

1976-01-01

335

Interplay between environmental and genetic factors in temperament/personality traits in horses (Equus caballus).  

Science.gov (United States)

The aim of the present study was to broach the question of the relative influence of different genetic and environmental factors on different temperament/personality traits of horses (Equus caballus). The researchers submitted 702 horses to standardized experimental tests and investigated 9 factors, either genetic or environmental. Genetic factors, such as sire or breed, seemed to influence more neophobic reactions, whereas environmental factors, such as the type of work, seemed to play a more dominant role in reactions to social separation or learning abilities. Additive effects were evident, showing how environmental factors may modulate behavioral traits. This study constitutes a first step toward understanding the relative weights of genetic factors and how the environment may intervene in determining individual behavioral characteristics. PMID:15584780

Hausberger, Martine; Bruderer, Cécile; Le Scolan, Nathalie; Pierre, Jean-Sébastien

2004-12-01

336

Ocorrência de anticorpos anti-Neospora spp. em jumentos (Equus asinus) no estado de Sucre - Colômbia / Occurrence of anti-Neospora spp. Antibodies in donkeys (Equus asinus) in the state of Sucre - Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A neosporose tem grande importância em bovinos, e sua patogênese neste hospedeiro, em termos gerais, está esclarecida, porém, em equídeos é pobremente conhecida. Na Colômbia ainda não foram reportados anticorpos Anti-Neospora spp. em equídeos, sendo assim objetivou-se no presente estudo avaliar a oc [...] orrência do parasito em jumentos (Equus asinus) de fazendas que apresentavam risco da doença nestes animais. Foram utilizados 56 animais no estado de Sucre (Colômbia), escolhidos aleatoriamente dentro das fazendas selecionadas. Utilizou-se um peptídeo recombinante originado de Neospora caninum (NcGRA1) para o diagnóstico por Dot-ELISA, e o soro foi diluído em 1:200. Este estudo reporta, pela primeira vez no estado de Sucre e na Colômbia, a presença de anticorpos anti-Neospora spp. na espécie Equus asinus, com uma ocorrência de 19,7% (11/56) dos animais amostrados. Abstract in english The neosporosis has great importance in cattle, and its pathogenesis in this host has been generally clarified, however, in horses, neosporosis is poorly known, and in Colombia anti-Neospora spp antibodies have not been reported. Therefore, the main objective in the present study was to evaluate the [...] occurrence of this parasite in donkeys (Equus asinus) from farms that presented a risk of disease in these animals, as well as no health plan for them. Were used 56 animals randomly chosen inside selected farms in the state of Sucre (Colombia). A recombinant peptide originated from Neospora caninum (NcGRA1) was used for the diagnosis with Dot-ELISA and serum was diluted 1:200. This study is the first to report the presence of anti-Neospora spp. in donkeys (Equus asinus) in the state of Sucre, and in Colombia. The occurrence was in 19.7% of the animals sampled (11/56).

R.D., Blanco; J.H., Patarroyo; M.I., Vargas; J.A., Cardona; L.S., Araújo; V.E., Gomez.

337

Ocorrência de anticorpos anti-Neospora spp. em jumentos (Equus asinus) no estado de Sucre - Colômbia / Occurrence of anti-Neospora spp. Antibodies in donkeys (Equus asinus) in the state of Sucre - Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A neosporose tem grande importância em bovinos, e sua patogênese neste hospedeiro, em termos gerais, está esclarecida, porém, em equídeos é pobremente conhecida. Na Colômbia ainda não foram reportados anticorpos Anti-Neospora spp. em equídeos, sendo assim objetivou-se no presente estudo avaliar a oc [...] orrência do parasito em jumentos (Equus asinus) de fazendas que apresentavam risco da doença nestes animais. Foram utilizados 56 animais no estado de Sucre (Colômbia), escolhidos aleatoriamente dentro das fazendas selecionadas. Utilizou-se um peptídeo recombinante originado de Neospora caninum (NcGRA1) para o diagnóstico por Dot-ELISA, e o soro foi diluído em 1:200. Este estudo reporta, pela primeira vez no estado de Sucre e na Colômbia, a presença de anticorpos anti-Neospora spp. na espécie Equus asinus, com uma ocorrência de 19,7% (11/56) dos animais amostrados. Abstract in english The neosporosis has great importance in cattle, and its pathogenesis in this host has been generally clarified, however, in horses, neosporosis is poorly known, and in Colombia anti-Neospora spp antibodies have not been reported. Therefore, the main objective in the present study was to evaluate the [...] occurrence of this parasite in donkeys (Equus asinus) from farms that presented a risk of disease in these animals, as well as no health plan for them. Were used 56 animals randomly chosen inside selected farms in the state of Sucre (Colombia). A recombinant peptide originated from Neospora caninum (NcGRA1) was used for the diagnosis with Dot-ELISA and serum was diluted 1:200. This study is the first to report the presence of anti-Neospora spp. in donkeys (Equus asinus) in the state of Sucre, and in Colombia. The occurrence was in 19.7% of the animals sampled (11/56).

R.D., Blanco; J.H., Patarroyo; M.I., Vargas; J.A., Cardona; L.S., Araújo; V.E., Gomez.

2014-04-01

338

POST-HATCH ORAL ESTROGEN EXPOSURE IMPAIRS ADULT REPRODUCTIVE PERFORMANCE OF ZEBRA FINCH IN A SEX-SPECIFIC MANNER. (R825294)  

Science.gov (United States)

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

339

Young and intense: FoxP2 immunoreactivity in Area X varies with age, song stereotypy, and singing in male zebra finches  

Directory of Open Access Journals (Sweden)

Full Text Available FOXP2 is a transcription factor functionally relevant for learned vocalizations in humans and songbirds. In songbirds, FoxP2 mRNA expression in the medium spiny neurons of the basal ganglia song nucleus Area X is developmentally regulated and varies with singing conditions in different social contexts. How individual neurons in Area X change FoxP2 expression across development and in social contexts is not known, however. Here we address this critical gap in our understanding of FoxP2 as a link between neuronal networks and behavior. We used a statistically unbiased analysis of FoxP2-immunoreactivity (IR on a neuron-by-neuron basis and found a bimodal distribution of FoxP2-IR neurons in Area X: weakly-stained and intensely-stained. The density of intensely-stained FoxP2-IR neurons was 10 times higher in juveniles than in adults, exponentially decreased with age, and was negatively correlated with adult song stability. Three-week old neurons labeled with BrdU were more than five times as likely to be intensely-stained than weakly-stained. The density of FoxP2-IR putative migratory neurons with fusiform-shaped nuclei substantially decreased as birds aged. The density of intensely-stained FoxP2-IR neurons was not affected by singing whereas the density of weakly-stained FoxP2-IR neurons was. Together, these data indicate that young Area X medium spiny neurons express FoxP2 at high levels and decrease expression as they become integrated into existing neural circuits. Once integrated, levels of FoxP2 expression correlate with singing behavior. Together, these findings raise the possibility that FoxP2 levels may orchestrate song learning and song stereotypy in adults by a common mechanism.

ChristopherKirkThompson

2013-02-01

340

Testing of five methods for the control of zebra mussels in cooling circuits of power plants located on the Moselle river  

International Nuclear Information System (INIS)

Bioassays have been conducted on site at the Cattenom nuclear power plant located on the Moselle River (in northeast France) to control mussels in auxiliary plant circuits. During the course of a two-year program, five methods were tested: - thermal treatment (33 deg to 40 deg C), - high dosage chlorination (> 50 ppm), - low dosage chlorine dioxide, - potassium salt (KCI > 100 ppm), - one organic compound (Mexel 432). This note presents a comparison of the treatments shown to be most effective, on the basis of technical feasibility, cost and environmental acceptability. (author). 8 figs., 10 refs., 3 tabs

 
 
 
 
341

Variation in faecal water content may confound estimates of gastro-intestinal parasite intensity in wild African herbivores  

Science.gov (United States)

Estimates of parasite intensity within host populations are essential for many studies of host-parasite relationships. Here we evaluated the seasonal, age- and sex-related variability in faecal water content for two wild ungulate species, springbok (Antidorcas marsupialis) and plains zebra (Equus quagga). We then assessed whether or not faecal water content biased conclusions regarding differences in strongyle infection rates by season, age or sex. There was evidence of significant variation in faecal water content by season and age for both species, and by sex in springbok. Analyses of faecal egg counts demonstrated that sex was a near-significant factor in explaining variation in strongyle parasite infection rates in zebra (P = 0.055) and springbok (P = 0.052) using wet-weight faecal samples. However, once these intensity estimates were re-scaled by the percent of dry matter in the faeces, sex was no longer a significant factor (zebra, P = 0.268; springbok, P = 0.234). These results demonstrate that variation in faecal water content may confound analyses and could produce spurious conclusions, as was the case with host sex as a factor in the analysis. We thus recommend that researchers assess whether water variation could be a confounding factor when designing and performing research using faecal indices of parasite intensity. PMID:19627626

Turner, W.C.; Cizauskas, C.A.; Getz, W.M.

2010-01-01

342

A vegetation description and floristic analyses of the springs on the Kammanassie Mountain, Western Cape  

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Full Text Available The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.

G.J. Bredenkamp

2004-12-01

343

Holocene extinction dynamics of Equus hydruntinus, a late-surviving European megafaunal mammal  

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The European wild ass (Equus hydruntinus) is a globally extinct Eurasian equid. This species was widespread in Europe and southwest Asia during the Late Pleistocene, but its distribution became restricted to southern Europe and adjacent geographic regions in the Holocene. Previous research on E. hydruntinus has focused predominantly on its taxonomy and Late Pleistocene distribution. However, its Holocene distribution and extinction remain poorly understood, despite the fact that the European wild ass represents one of Europe's very few globally extinct Holocene megafaunal mammal species. We summarise all available Holocene zooarchaeological spatio-temporal occurrence data for the species, and analyse patterns of its distribution and extinction using point pattern analysis (kernel density estimation and Clark Evans index) and optimal linear estimation. We demonstrate that the geographic range of E. hydruntinus became highly fragmented into discrete subpopulations during the Holocene, which were associated with separate regions of open habitat and which became progressively extinct between the Neolithic and Iron Age. These data challenge previous suggestions of the late survival of E. hydruntinus into the medieval period in Spain, and instead suggest that postglacial climate-driven vegetational changes were a primary factor responsible for extinction of the species, driving isolation of small remnant subpopulations that may have been increasingly vulnerable to human exploitation. This study contributes to a more nuanced understanding of Late Quaternary species extinctions in Eurasia, suggesting that they were temporally staggered and distinct in their respective extinction trajectories.

Crees, Jennifer J.; Turvey, Samuel T.

2014-05-01

344

Interspecific communication from people to horses (Equus ferus caballus) is influenced by different horsemanship training styles.  

Science.gov (United States)

The ability of many domesticated animals to follow human pointing gestures to locate hidden food has led to scientific debate on the relative importance of domestication and individual experience on the origins and development of this capacity. To further explore this question, we examined the influence of different prior training histories/methods on the ability of horses (Equus ferus caballus) to follow a momentary distal point. Ten horses previously trained using one of two methods (Parelli™ natural horsemanship or traditional horse training) were tested using a standard object choice task. The results show that neither group of horses was initially able to follow the momentary distal point. However, after more experience with the point, horses previously trained using the Parelli natural horsemanship method learned to follow momentary distal points significantly faster than those previously trained with traditional methods. The poor initial performance of horses on distal pointing tasks, coupled with the finding that prior training history and experimental experience can lead to success on this task, fails to support the predictions of the domestication hypothesis and instead lends support to the two-stage hypothesis. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25111631

Dorey, Nicole R; Conover, Alicia M; Udell, Monique A R

2014-11-01

345

Dietary overlap among kulan Equus hemionus, goitered gazelle Gazella subgutturosa and livestock  

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Full Text Available We studied overlap among diets of kulan Equus hemionus, goitered gazelle Gazella subgutturosa sairensis and three domestic livestock, using micro-histological analysis of fresh fecal samples collected in the Kalamaili Ungulate Nature Reserve, Xinjiang, China during autumn and winter 2007, and spring 2008. Kulan, goitred gazelle and domestic livestock mainly ate Stipa spp., Ceratoides lateens, Artemisia spp. and white saxaul Haloxylon persicum, although plant families and species compositions of their diets differed. Pianka Niche Overlap Index C values of kulan, goitered gazelle, and 3 domestic livestock species were all over 0.8, varying from 0.832 (between goitered gazelle and domestic horse in winter to 0.986 (between kulan and domestic sheep in autumn, and between domestic horse and domestic sheep in autumn. We interpret these high overlap values as indicating serious food competition among wild animals and seasonal pastoral livestock, especially, during winters when deep snow covered ground and forage was scarce. Wild ungulates may be die due to malnutrition during those severe winters. Thus we recommend that managers of Kalamaili Ungulate Nature Reserve should set up guidelines for restricting the number of livestock entering the nature reserve in autumn, or restricting the grazing area of livestock in winter, and protecting wild ungulates in the nature reserve [Acta Zoologica Sinica 54(6?941– 954, 2008].

CHU Hong-Jun

2008-12-01

346

Evaluación clínica e histopatológica de la pitiosis cutánea en burros (Equus asinus) / Clinical and Histopathological Evaluation of Cutaneous Pythiosis in Donkeys (Equusasinus) / Avaliação clínica e histopatológica da pitiose cutânea em burros (Equus asinus)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese O objetivo deste estudo foi avaliar e caracterizar os aspectos clínicos e histopatológicos da pitiose cutânea em burros (Equus asinus) no Estado de Córdoba, Colômbia. Realizou-se um estudo de tipo descritivo, não probabilístico em animais de conveniência. Foram analisados nove burros com pitiose cut [...] ânea, diagnosticados clínica e histopatologicamente. Ao descrever os casos se observou uma grave ulceração granulomatose em forma de cratera com tecido necrótico, aparência tumoral, abundante exsudação pegajosa fibrinosa sanguinolenta e saída de material caseoso de cor branca amarelada denominada kunkers. As lesões se localizaram em membros, abdômen ventral e peito dos animais. Histopatologicamente, com a coloração de hematoxilina-eosina, se observou dermatite pio granulomatosa severa, com abundante infiltrado inflamatório de tipo eosinofílico e neutrofílico; com a coloração de Grocott se evidenciaram hifas com tabiques e parcialmente ramificadas em ângulo reto, de cor marrom. O diagnóstico definitivo da doença se fundamentou nas características clínicas, o diagnóstico diferencial e nos achados histopatológicos. Foi concluinte o diagnóstico da pitiose cutânea. O presente estudo se converte no primeiro relatório desta doença em burros (Equus asinus) no Estado de Córdoba na Colômbia. Abstract in spanish El objetivo de este estudio fue evaluar y caracterizar los aspectos clínicos e histopatológicos de la pitiosis cutánea en burros (Equus asinus) en el departamento de Córdoba, Colombia. Se realizó un estudio de tipo descriptivo, no probabilístico en animales de conveniencia. Fueron analizados nueve b [...] urros con pitiosis cutánea diagnosticados clínica e histopatológicamente. Al describir los casos se observó una grave ulceración granulomatosa en forma de cráter, con tejido necrótico, apariencia tumoral, abundante exudación filante fibrino-sanguinolenta y salida de material caseificado de color blanco amarillento denominado kunkers. Las lesiones se ubicaron en miembros, abdomen ventral y pecho de los animales. Histopatológicamente, con la coloración de hematoxilina-eosina, se observó dermatitis piogranulomatosa severa, con abundante infiltrado inflamatorio de tipo eosinofílico y neutrofílico; con la coloración de Grocott se evidenciaron hifas con tabiques y parcialmente ramificadas en ángulo recto, de color café. El diagnóstico definitivo de la enfermedad se fundamentó en las características clínicas, el diagnóstico diferencial y en los hallazgos histopatológicos. Fue concluyente el diagnóstico de la pitiosis cutánea. El presente estudio se convierte en el primer reporte de esta enfermedad en burros (Equus asinus) en el departamento de Córdoba y en Colombia. Abstract in english The purpose of this study was to evaluate and characterize the clinical and histopathological aspects of cutaneous pythiosis in donkeys (Equus asinus) in the Department of Cordoba, Colombia. A descriptive, non-probability study was conducted on domesticated animals. Nine donkeys clinically and histo [...] pathologically diagnosed with cutaneous pythiosis were analyzed. After describing the cases, a serious, crater-shaped granulomatous ulcer was observed, with necrotic tissue, a tumor appearance, abundant fibrinous-bloody exudation and yellowish-white caseous material known as kunkers. The lesions were found in the members, ventral abdomen and chest of the animals. Histopathologically, with the hematoxylin-eosin staining, severe pyogranulomatous dermatitis was observed, with abundant eosinophilic and neutrophilic inflammatory infiltrate; with the Grocott staining, hyphae with septa were found, partially branching into a right angle and brown in color. The definitive diagnosis of the disease was based on the clinical features, the differential diagnosis and the histopathological findings. The diagnosis of cutaneous pythiosis was conclusive. This study becomes the first report of this disease in donkeys

José Alberto, Cardona Álvarez; Marlene Isabel, Vargas Viloria; Sandra Carolina, Perdomo Ayola.

347

Evaluación clínica e histopatológica de la pitiosis cutánea en burros (Equus asinus) / Clinical and Histopathological Evaluation of Cutaneous Pythiosis in Donkeys (Equusasinus) / Avaliação clínica e histopatológica da pitiose cutânea em burros (Equus asinus)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese O objetivo deste estudo foi avaliar e caracterizar os aspectos clínicos e histopatológicos da pitiose cutânea em burros (Equus asinus) no Estado de Córdoba, Colômbia. Realizou-se um estudo de tipo descritivo, não probabilístico em animais de conveniência. Foram analisados nove burros com pitiose cut [...] ânea, diagnosticados clínica e histopatologicamente. Ao descrever os casos se observou uma grave ulceração granulomatose em forma de cratera com tecido necrótico, aparência tumoral, abundante exsudação pegajosa fibrinosa sanguinolenta e saída de material caseoso de cor branca amarelada denominada kunkers. As lesões se localizaram em membros, abdômen ventral e peito dos animais. Histopatologicamente, com a coloração de hematoxilina-eosina, se observou dermatite pio granulomatosa severa, com abundante infiltrado inflamatório de tipo eosinofílico e neutrofílico; com a coloração de Grocott se evidenciaram hifas com tabiques e parcialmente ramificadas em ângulo reto, de cor marrom. O diagnóstico definitivo da doença se fundamentou nas características clínicas, o diagnóstico diferencial e nos achados histopatológicos. Foi concluinte o diagnóstico da pitiose cutânea. O presente estudo se converte no primeiro relatório desta doença em burros (Equus asinus) no Estado de Córdoba na Colômbia. Abstract in spanish El objetivo de este estudio fue evaluar y caracterizar los aspectos clínicos e histopatológicos de la pitiosis cutánea en burros (Equus asinus) en el departamento de Córdoba, Colombia. Se realizó un estudio de tipo descriptivo, no probabilístico en animales de conveniencia. Fueron analizados nueve b [...] urros con pitiosis cutánea diagnosticados clínica e histopatológicamente. Al describir los casos se observó una grave ulceración granulomatosa en forma de cráter, con tejido necrótico, apariencia tumoral, abundante exudación filante fibrino-sanguinolenta y salida de material caseificado de color blanco amarillento denominado kunkers. Las lesiones se ubicaron en miembros, abdomen ventral y pecho de los animales. Histopatológicamente, con la coloración de hematoxilina-eosina, se observó dermatitis piogranulomatosa severa, con abundante infiltrado inflamatorio de tipo eosinofílico y neutrofílico; con la coloración de Grocott se evidenciaron hifas con tabiques y parcialmente ramificadas en ángulo recto, de color café. El diagnóstico definitivo de la enfermedad se fundamentó en las características clínicas, el diagnóstico diferencial y en los hallazgos histopatológicos. Fue concluyente el diagnóstico de la pitiosis cutánea. El presente estudio se convierte en el primer reporte de esta enfermedad en burros (Equus asinus) en el departamento de Córdoba y en Colombia. Abstract in english The purpose of this study was to evaluate and characterize the clinical and histopathological aspects of cutaneous pythiosis in donkeys (Equus asinus) in the Department of Cordoba, Colombia. A descriptive, non-probability study was conducted on domesticated animals. Nine donkeys clinically and histo [...] pathologically diagnosed with cutaneous pythiosis were analyzed. After describing the cases, a serious, crater-shaped granulomatous ulcer was observed, with necrotic tissue, a tumor appearance, abundant fibrinous-bloody exudation and yellowish-white caseous material known as kunkers. The lesions were found in the members, ventral abdomen and chest of the animals. Histopathologically, with the hematoxylin-eosin staining, severe pyogranulomatous dermatitis was observed, with abundant eosinophilic and neutrophilic inflammatory infiltrate; with the Grocott staining, hyphae with septa were found, partially branching into a right angle and brown in color. The definitive diagnosis of the disease was based on the clinical features, the differential diagnosis and the histopathological findings. The diagnosis of cutaneous pythiosis was conclusive. This study becomes the first report of this disease in donkeys

José Alberto, Cardona Álvarez; Marlene Isabel, Vargas Viloria; Sandra Carolina, Perdomo Ayola.

2013-06-01

348

Groundwater-flow parameter estimation and quality modeling of the Equus Beds aquifer in Kansas, U.S.A.  

Science.gov (United States)

The salinity problems created in the Burrton area as a result of poor oil-field brine disposal practices of the past continue to be a major concern to the area depending on the Equus Beds aquifer for water, including the City of Wichita, Kansas. In this paper, an attempt is made to predict where and how fast the brine plume will move in this area, and what the average chloride concentrations in different parts of the aquifer are. In order to make such predictions, it was necessary to get a calibrated model of the groundwater-flow velocity field. Multiple regression analysis is used for parameter estimation of the steady-state groundwater-flow equation applied in the most critical area of the Equus Beds aquifer. Results of such an analysis produced a correlation coefficient of 0.992 between calculated and observed values of hydraulic head. A chloride transport modeling effort is then carried out despite some serious data deficiencies, the significance of which are evaluated through sensitivity analysis. Thus, starting with the quasi steady-state conditions of the early 1940's, it was possible to match the present chloride distribution satisfactorily. Chloride concentration predictions made for the year 2000 indicate that the quality of the Wichita well-field waters will not generally deteriorate from their present condition by that time. ?? 1984.

Sophocleous, M.A.

1984-01-01

349

Presencia de Equus (Amerhippus neogeus Lund en el yacimiento paleontológico de Pehuen Có (Pleistoceno tardío de la provincia de Buenos Aires y su significado bioestratigráfico Occurrence of Equus (Amerhippus neogeus Lund in the paleontological site of Pehuen Có (Late Pleistocene of the Province of Buenos Aires and its biostratigraphic implications  

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Full Text Available Se comunica el hallazgo de material paleontológico asignado a Equus (Amerhippus neogeus Lund en la localidad de Pehuen Có, provincia de Buenos Aires. La importancia del registro radica en que se trata del primer équido descripto en esta localidad, verificándose la edad pleistocena tardía (Lujanense de los sedimentos portadores, anteriormente obtenida mediante métodos radimétricos.The record of fossil material assigned to Equus (Amerhippus neogeus in Pehuen Có, Buenos Aires province, is presented. This record is important because it represents the first equid described from the locality, and verifies the Late Pleistocene age of the sediments (Lujanean, obtained earlier by radiometric methods.

R. Rodríguez Brizuela

2005-09-01

350

Taxonomía y hábito alimentario de Equus conversidens (Perissodactyla, Equidae) del Pleistoceno Tardío (Rancholabreano) de Hidalgo, centro de México / Taxonomy and dietary behavior of Equus conversidens (Perissodactyla, Equidae) from the late Pleistocene (Rancholabream) of Hidalgo, central Mexico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El estudio comparado de material craneal y dental perteneciente a équidos, recuperado de sedimentos pleistocénicos innominados de origen fluvio-lacustre ubicados en la parte suroriental de Hidalgo, permitió caracterizar y asignar la muestra disponible a Equus conversidens. Este registro aporta evide [...] ncia adicional acerca de la amplia distribución que tuvo esta especie a lo largo del territorio nacional y del subcontinente Norteamericano en conjunto durante los últimos dos millones de años. Por otra parte, la interpretación del hábito alimentario mediante la implementación del método de mesodesgaste, reveló que el patrón de desgaste observado en los elementos dentales considerados en el análisis, caracterizado por una combinación de relieve oclusal bajo y cúspides romas, es estrechamente cercano al que distingue a la especie pacedora reciente Bison bison. Los resultados obtenidos indican que la población de équidos hidalguense tuvo una dieta conformada predominantemente por recursos abrasivos con un alto contenido de sílice y/o fitolitos (pastos, polvo y/o arena). El comportamiento alimentario propuesto evidencia la presencia de zonas de vegetación abierta en lo que ahora es parte del centro de México durante la segunda mitad del Pleistoceno; aunado a esto, las formas herbívoras asociadas al registro de équidos sugieren que, además de áreas donde posiblemente predominaron los pastos y otras herbáceas, también existieron zonas más arboladas, lo cual es indicativo de un hábitat heterogéneo. Abstract in english A comparative study of equid cranial and dental material, recovered from unnamed fluvio-lacustrine deposits of late Pleistocene age that crop out in southeastern Hidalgo, allowed to assign the fossil sample to Equus conversidens. The record gives additional evidence on the widespread distribution of [...] this species throughout the North American subcontinent during the last two million years. On the other hand, we evaluated the dietary behavior of this Equus population from Hidalgo by the extended mesowear analysis method. The observed mesowear pattern is comparable to that of the recent grazer species Bison bison. These species display a particular combination of low occlusal relief and blunt cusps. This suggests that the horse population from Hidalgo was a grass feeder that incoporated abrasive food items into its diet (grass and/or extrinsic grit). The results provide evidence for the existence of local grazing habitats in central Mexico during the late Pleistocene; furthermore, the associated herbivore fauna indicates wooded areas as well, thus suggesting a heterogeneous habitat.

Víctor M., Bravo-Cuevas; Eduardo, Jiménez-Hidalgo; Jaime, Priego-Vargas.

2011-04-01

351

Taxonomía y hábito alimentario de Equus conversidens (Perissodactyla, Equidae) del Pleistoceno Tardío (Rancholabreano) de Hidalgo, centro de México / Taxonomy and dietary behavior of Equus conversidens (Perissodactyla, Equidae) from the late Pleistocene (Rancholabream) of Hidalgo, central Mexico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El estudio comparado de material craneal y dental perteneciente a équidos, recuperado de sedimentos pleistocénicos innominados de origen fluvio-lacustre ubicados en la parte suroriental de Hidalgo, permitió caracterizar y asignar la muestra disponible a Equus conversidens. Este registro aporta evide [...] ncia adicional acerca de la amplia distribución que tuvo esta especie a lo largo del territorio nacional y del subcontinente Norteamericano en conjunto durante los últimos dos millones de años. Por otra parte, la interpretación del hábito alimentario mediante la implementación del método de mesodesgaste, reveló que el patrón de desgaste observado en los elementos dentales considerados en el análisis, caracterizado por una combinación de relieve oclusal bajo y cúspides romas, es estrechamente cercano al que distingue a la especie pacedora reciente Bison bison. Los resultados obtenidos indican que la población de équidos hidalguense tuvo una dieta conformada predominantemente por recursos abrasivos con un alto contenido de sílice y/o fitolitos (pastos, polvo y/o arena). El comportamiento alimentario propuesto evidencia la presencia de zonas de vegetación abierta en lo que ahora es parte del centro de México durante la segunda mitad del Pleistoceno; aunado a esto, las formas herbívoras asociadas al registro de équidos sugieren que, además de áreas donde posiblemente predominaron los pastos y otras herbáceas, también existieron zonas más arboladas, lo cual es indicativo de un hábitat heterogéneo. Abstract in english A comparative study of equid cranial and dental material, recovered from unnamed fluvio-lacustrine deposits of late Pleistocene age that crop out in southeastern Hidalgo, allowed to assign the fossil sample to Equus conversidens. The record gives additional evidence on the widespread distribution of [...] this species throughout the North American subcontinent during the last two million years. On the other hand, we evaluated the dietary behavior of this Equus population from Hidalgo by the extended mesowear analysis method. The observed mesowear pattern is comparable to that of the recent grazer species Bison bison. These species display a particular combination of low occlusal relief and blunt cusps. This suggests that the horse population from Hidalgo was a grass feeder that incoporated abrasive food items into its diet (grass and/or extrinsic grit). The results provide evidence for the existence of local grazing habitats in central Mexico during the late Pleistocene; furthermore, the associated herbivore fauna indicates wooded areas as well, thus suggesting a heterogeneous habitat.

Víctor M., Bravo-Cuevas; Eduardo, Jiménez-Hidalgo; Jaime, Priego-Vargas.

352

Improved sperm cryosurvival in diluents containing amides versus glycerol in the Przewalski's horse (Equus ferus przewalskii).  

Science.gov (United States)

Two studies were conducted to understand sperm cryosensitivity in an endangered equid, the Przewalski's horse (Equus ferus przewalski), while testing the cryoprotectant ability of formamides. The first assessed the toxicity of permeating cryoprotectants (glycerol, methylformamide [MF] and dimethylformamide [DMF]) to Przewalski's horse spermatozoa during liquid storage at 4°C. The second examined the comparative influence of three diluents (with or without formamides) on cryosurvival of sperm from the Przewalski's versus domestic horse. When Przewalski's horse spermatozoa were incubated at 4°C in INRA 96 with differing concentrations of glycerol, MF or DMF or a combination of these amides, cells tolerated all but the highest concentration (10% v/v) of MF alone or in combination with DMF, both of which decreased (Psperm acrosomal integrity. In the cryosurvival study, average sperm motility and proportion of cells with intact acrosomes in fresh ejaculates were similar (P>0.05) between the Przewalski's (67%, 84%, respectively) and domestic (66%, 76%) horse donors. Sperm from both species were diluted in lactose-EDTA-glycerol (EQ), Botu-Crio (BOTU; a proprietary product containing glycerol and MF) or SM (INRA 96 plus 2% [v/v] egg yolk and 2.5% [v/v] MF and DMF) and then frozen over liquid nitrogen vapor. After thawing, the highest values recovered for total and progressive sperm motility, acrosomal integrity and mitochondrial membrane potential were 42.4%, 21.8%, 88.7% and 25.4CN (CN=mean JC-1 fluorescence intensity/cell on a channel number scale), respectively, in the Przewalski's and 49.3%, 24.6%, 88.9% and 25.8CN, respectively, in the domestic horse. Although sperm progressive motility and acrosome integrity did not differ (P>0.05) among treatments across species, mitochondrial membrane potential was higher (Psperm expressed higher (Phorse. In summary, Przewalski's stallion sperm benefit from exposure to either MF or DMF as an alternative cryoprotectant to glycerol. Overt sperm quality appears similar between the Przewalski's and domestic horse, although the total motility of cells from the former appears more sensitive to certain freezing diluents. Nonetheless, post-thaw motility and acrosomal integrity values for Przewalski's horse spermatozoa mimic findings in the domestic horse in the presence of INRA 96 supplemented with 2% (v/v) egg yolk and a combined 2.5% concentration of MF and DMF. PMID:24508651

Pukazhenthi, Budhan S; Johnson, Aime; Guthrie, H David; Songsasen, Nucharin; Padilla, Luis R; Wolfe, Barbara A; da Silva, Marco Coutinho; Alvarenga, Marco A; Wildt, David E

2014-04-01

353

Injection-Site Reactions in Wild Horses (Equus caballus) Receiving an Immunocontraceptive Vaccine  

Science.gov (United States)

The U.S. Geological Survey and the Bureau of Land Management are conducting research on the efficacy of the immunocontraceptive agent porcine zona pellucida (PZP) in reducing fertility of wild horses (Equus caballus). As an antigen, PZP stimulates antibody production when injected into many mammalian species. These antibodies bind to the external surface of the ovum, preventing fertilization. By itself, PZP is only weakly immunogenic and is therefore delivered with an adjuvant, most commonly one of the Freund adjuvants, designed to further stimulate antibody production. Freund's complete adjuvant (FCA) in particular is known to be very effective, but may also be associated with undesirable side effects such as formation of abscesses at injection sites. Such reactions may be exacerbated when accompanied by the additional trauma of a remotely delivered dart. Because horses in our three study herds were individually identifiable by color markings and harem association, we were able to monitor mares for injection-site reactions (abscesses, nodules, swelling, and stiffness) following inoculation with PZP. In 100 injections delivered by hand we observed a single nodule, two instances of swelling, and no other reactions. In two herds that received remotely delivered (dart) injections, the frequency of reactions was about 1 and 6 percent for abscesses, 25 percent for nodules (both herds), 11 and 33 percent for swelling, and 1 and 12 percent for stiffness. Abscesses were too infrequent to allow meaningful analysis of the relation to covariates, but for the other types of reactions we used logistic regression to examine the relation of occurrence to the delivery method (rifle or CO2-powered blowgun), adjuvant (FCA, Freund's modified adjuvant, and Freund's incomplete adjuvant), dart trauma (normal or abnormal), and age of mare. Abnormal dart trauma included cases where the dart hit bone or the needle broke off. We found strong evidence (odds ratio = 5.023, P = 0.001) for a higher probability of occurrence of swelling when darts were delivered by blowgun. We found some evidence (odds ratio = 8.729, P = 0.07) that abnormal dart trauma led to a higher frequency of nodule formation. Nodules were the most common reactions observed and often persisted for a year or more, but in our observations they did not appear to change any animal's range of movement or locomotor patterns and in most cases did not appear to differ in magnitude from naturally occurring injuries or scars. We were unable to perform histological examinations of these nodules, but they may be similar to granulomas reported by other investigators following administration of Freund's adjuvant.

Roelle, James E.; Ransom, Jason I.

2009-01-01

354

A new record of Equus (Mammalia: Equidae from the Late Pleistocene of central-south Chile Un nuevo registro de Equus (Mammalia: Equidae para el Pleistoceno Superior de Osorno, Chile  

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Full Text Available Fourteen dental and bone parts of a horse excavated from the Pilauco paleontological site, Osorno (40°39' S-73°07' W are analysed and interpreted. This site was formed in association with a peat bog located on the banks of the old Damas River and has conserved abundant late Pleistocene mammalian fauna and flora materials. A date of 11457 ± 140 14C yrs B.P. was obtained from a molar and agrees with our stratigraphic age model. We have identified the fossils as pertaining to the species Equus (Amerhippus andium, which confirms its presence in central-south Chile. Furthermore, the recorded geographic location indicate that the metapodial adaptations of the specimens previously described agree with the reconstructed late Pleistocene landscape of Pilauco, dominated by soft volcanic soils and isolated forest patches over large extensions of grasslands.Se analizan e interpretan 14 fósiles correspondientes a dientes y huesos de caballo registrados en el sitio Pilauco, Osorno (40°39' S-73°07' W. El sitio se formó asociado a un pantano en un borde del antiguo río Damas; en él se ha conservado abundante material de mastofauna y flora pleistocénica. Una fecha radiocarbónica de 11457 ± 140 A.P obtenida de un molar, es concordante con el modelo de edad del sitio. La identificación taxonómica permite asociar a los fósiles a la especie Equus (Amerhippus andium, lo que confirma la presencia de la especie en el centro-sur de Chile. Por otra parte, la posición geográfica de los hallazgos y la reconstrucción del paisaje indicarían que se trata de ejemplares cuyas adaptaciones en los metapodios son concordantes para el paisaje pleistocénico de Pilauco dominado por suelos volcánicos blandos, con presencia de bosquetes dispersos en grandes extensiones de praderas de gramíneas.

OMAR P RECABARREN

2011-12-01

355

A new record of Equus (Mammalia: Equidae) from the Late Pleistocene of central-south Chile / Un nuevo registro de Equus (Mammalia: Equidae) para el Pleistoceno Superior de Osorno, Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Se analizan e interpretan 14 fósiles correspondientes a dientes y huesos de caballo registrados en el sitio Pilauco, Osorno (40°39' S-73°07' W). El sitio se formó asociado a un pantano en un borde del antiguo río Damas; en él se ha conservado abundante material de mastofauna y flora pleistocénica. U [...] na fecha radiocarbónica de 11457 ± 140 A.P obtenida de un molar, es concordante con el modelo de edad del sitio. La identificación taxonómica permite asociar a los fósiles a la especie Equus (Amerhippus) andium, lo que confirma la presencia de la especie en el centro-sur de Chile. Por otra parte, la posición geográfica de los hallazgos y la reconstrucción del paisaje indicarían que se trata de ejemplares cuyas adaptaciones en los metapodios son concordantes para el paisaje pleistocénico de Pilauco dominado por suelos volcánicos blandos, con presencia de bosquetes dispersos en grandes extensiones de praderas de gramíneas. Abstract in english Fourteen dental and bone parts of a horse excavated from the Pilauco paleontological site, Osorno (40°39' S-73°07' W) are analysed and interpreted. This site was formed in association with a peat bog located on the banks of the old Damas River and has conserved abundant late Pleistocene mammalian fa [...] una and flora materials. A date of 11457 ± 140 14C yrs B.P. was obtained from a molar and agrees with our stratigraphic age model. We have identified the fossils as pertaining to the species Equus (Amerhippus) andium, which confirms its presence in central-south Chile. Furthermore, the recorded geographic location indicate that the metapodial adaptations of the specimens previously described agree with the reconstructed late Pleistocene landscape of Pilauco, dominated by soft volcanic soils and isolated forest patches over large extensions of grasslands.

OMAR P, RECABARREN; MARIO, PINO; INÉS, CID.

2011-12-01

356

A new record of Equus (Mammalia: Equidae) from the Late Pleistocene of central-south Chile / Un nuevo registro de Equus (Mammalia: Equidae) para el Pleistoceno Superior de Osorno, Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Se analizan e interpretan 14 fósiles correspondientes a dientes y huesos de caballo registrados en el sitio Pilauco, Osorno (40°39' S-73°07' W). El sitio se formó asociado a un pantano en un borde del antiguo río Damas; en él se ha conservado abundante material de mastofauna y flora pleistocénica. U [...] na fecha radiocarbónica de 11457 ± 140 A.P obtenida de un molar, es concordante con el modelo de edad del sitio. La identificación taxonómica permite asociar a los fósiles a la especie Equus (Amerhippus) andium, lo que confirma la presencia de la especie en el centro-sur de Chile. Por otra parte, la posición geográfica de los hallazgos y la reconstrucción del paisaje indicarían que se trata de ejemplares cuyas adaptaciones en los metapodios son concordantes para el paisaje pleistocénico de Pilauco dominado por suelos volcánicos blandos, con presencia de bosquetes dispersos en grandes extensiones de praderas de gramíneas. Abstract in english Fourteen dental and bone parts of a horse excavated from the Pilauco paleontological site, Osorno (40°39' S-73°07' W) are analysed and interpreted. This site was formed in association with a peat bog located on the banks of the old Damas River and has conserved abundant late Pleistocene mammalian fa [...] una and flora materials. A date of 11457 ± 140 14C yrs B.P. was obtained from a molar and agrees with our stratigraphic age model. We have identified the fossils as pertaining to the species Equus (Amerhippus) andium, which confirms its presence in central-south Chile. Furthermore, the recorded geographic location indicate that the metapodial adaptations of the specimens previously described agree with the reconstructed late Pleistocene landscape of Pilauco, dominated by soft volcanic soils and isolated forest patches over large extensions of grasslands.

OMAR P, RECABARREN; MARIO, PINO; INÉS, CID.

357

First suckling: a crucial event for mother-young attachment? an experimental study in horses (Equus caballus).  

Science.gov (United States)

This study investigates the consequences of interference during first suckling for subsequent mare-young attachment in horses (Equus caballus). Foals brought to their dams' teats appeared, at later ages (1-3 months), to remain closer to their dams and to play less than control foals that had been allowed to suckle spontaneously. Higher levels of play and distance initiatives from the mother are considered criteria for secure attachment in horses, humans, and other species. As this unique handling was the only event that distinguished experimental from control groups, the authors concluded that first suckling is a crucial event in the development of secure dam-young attachment. These results could have important implications for all mammal species, including humans. PMID:17324081

Hausberger, Martine; Henry, Séverine; Larose, Claire; Richard-Yris, Marie-Annick

2007-02-01

358

First evidence of Equus asinus L. in the Chalcolithic disputes the Phoenicians as the first to introduce donkeys into the Iberian Peninsula  

DEFF Research Database (Denmark)

Two equid species have been documented in the Pleistocene of the Iberian Peninsula, the horse Equus caballus, and the Eurasian hemione Equus hydruntinus. While the former survived the Holocene–Pleistocene until now, the timing for the extinction of the latter is unclear. Scarce, fragmented archaeological remains assess the presence of small equids living in the Holocene of Iberia. Those could possibly correspond to the Eurasian hemione although unambiguous morphological identification is often not possible. With the find of an equid tooth from Leceia, a Chalcolithic fortified site in Portugal, and using both morphological and mitochondrial genome analyses, we demonstrate for the first time the presence of a new equid species in Holocene Iberia, namely a donkey (Equus asinus). Radiocarbon dating of the tooth to Cal 2340–2130, and 2080–2060 BC with 95% probability, demonstrates that donkeys were present in Iberia well before the arrival of Phoenicians in the first quarter of the first millennium BC (900–750 years BC), which were considered so far as the first who introduced donkeys in the region.

Cardoso, João L.; Vilstrup, Julia T

2013-01-01

359

Presencia de Equus (Amerhippus) neogeus Lund en el yacimiento paleontológico de Pehuen Có (Pleistoceno tardío de la provincia de Buenos Aires) y su significado bioestratigráfico / Occurrence of Equus (Amerhippus) neogeus Lund in the paleontological site of Pehuen Có (Late Pleistocene of the Province of Buenos Aires) and its biostratigraphic implications  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Se comunica el hallazgo de material paleontológico asignado a Equus (Amerhippus) neogeus Lund en la localidad de Pehuen Có, provincia de Buenos Aires. La importancia del registro radica en que se trata del primer équido descripto en esta localidad, verificándose la edad pleistocena tardía (Lujanense [...] ) de los sedimentos portadores, anteriormente obtenida mediante métodos radimétricos. Abstract in english The record of fossil material assigned to Equus (Amerhippus) neogeus in Pehuen Có, Buenos Aires province, is presented. This record is important because it represents the first equid described from the locality, and verifies the Late Pleistocene age of the sediments (Lujanean), obtained earlier by r [...] adiometric methods.

R., Rodríguez Brizuela.

360

Morphology and diagnosis of some fourth-stage larvae of cyathostomines (Nematoda: Strongyloidea) in donkeys Equus asinus L. from Ethiopia.  

Science.gov (United States)

Fourth-stage larvae of four species of the Cyathostominae Nicoll, 1927 parasitic in donkeys Equus asinus L. from Ethiopia were identified mainly using moulting specimens. They are Cylicocyclus asini Matthee, Krecek & Gibbons, 2001, C. auriculatus (Looss, 1900) Chaves, 1930, Cyathostomum tetracanthum (Mehlis, 1831) Molin, 1861 (sensu Looss, 1900) and Cylindropharynx brevicauda Leiper, 1911. The larva of Cylicocyclus asini is similar to those of C. nassatus (Looss, 1900) Chaves, 1930 and C. leptostomum Kotlán, 1920, but differs from the former by the shape of the dorsal tooth in the oesophageal funnel, which is notably smaller than in C. asini but similar to that of C. leptostomum. However, the larva of C. asini differs from that of C. leptostomum in the size of the buccal capsule, which is notably larger than in C. leptostomum but similar to that of C. nassatus. The larva of C. auriculatus is very similar to that of C. insigne (Boulenger, 1917) Chaves, 1930. The larva of Cyathostomum tetracanthum is similar to those of Cylicostephanus bidentatus (Ihle, 1925) Lichtenfels, 1975, C. goldi (Boulenger, 1917) Lichtenfels, 1975 and Cyathostomum catinatum Looss, 1900. The larva of Cylindropharynx brevicauda is similar to that of Petrovinema skrjabini (Ershov, 1930) Ershov, 1943 but smaller in size. Including the four cyathostomine species identified in the present study, 36 species belonging to 13 genera have so far been described and identified of a total of 64 recognised and confirmed species of equine strongyles. PMID:19048404

Kharchenko, Vitaliy; Kuzmina, Tetyana; Trawford, Andrew; Getachew, Mulugeta; Feseha, Gebreab

2009-01-01