Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
1.
Biodivers Genomes ; 20242024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38698932

RESUMO

We present the complete genome sequences of 12 species of Enteromius. Illumina sequencing was performed on genetic material from museum specimens. The reads were assembled using a de novo method followed by a finishing step. The raw and assembled data are publicly available via Genbank.

2.
J Econ Entomol ; 117(2): 417-426, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38412361

RESUMO

The arthropod intestinal tract and other anatomical parts naturally carry microorganisms. Some of which are pathogens, secrete toxins, or carry transferable antibiotic-resistance genes. The risks associated with the production and consumption of edible arthropods are dependent on indigenous microbes, as well as microbes introduced during the processes of rearing. This mass arthropod production puts individual arthropods in close proximity, which increases the possibility of their exposure to antibiotic-resistant bacteria carried by bacteria from fellow insects, industry workers, or rearing hardware and substrates. The purpose of this study was to determine if the alimentary tract of the yellow mealworm provided an environment permitting horizontal gene transfer between bacteria. The effect of the concentration of bacterial exposure was also assessed. Antibiotic resistance gene transfer between marker Salmonella Lignières (Enterobacterales: Enterobacteriaceae) and Escherichia coli (Migula) (Enterobacterales: Enterobacteriaceae) introduced into the larval gut demonstrated that the nutrient-rich environment of the yellow mealworm gut provided favorable conditions for the transfer of antibiotic resistance genes. Conjugation frequencies were similar across inoculum concentrations; however, transconjugant production correlated positively to increased exposure concentration. The lowest concentration of bacterial exposure required enrichment to detect and thus may have been approaching a threshold level for the 2 bacteria to colocate within the expanse of the larval gut. While many factors can affect this transfer, the simple factor of the proximity of donor and recipient bacteria, as defined by the concentration of bacteria within the volume of the insect gut, likely primarily contributed to the efficiency of antibiotic gene transfer.


Assuntos
Antibacterianos , Tenebrio , Animais , Antibacterianos/farmacologia , Tenebrio/genética , Tenebrio/microbiologia , Larva , Plasmídeos , Bactérias/genética , Insetos/genética , Resistência Microbiana a Medicamentos , Escherichia coli/genética
3.
J Mol Biol ; 435(20): 168259, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37660941

RESUMO

An important pathogenicity factor of SARS-CoV-2 and related coronaviruses is Non-structural protein 1 (Nsp1), which suppresses host gene expression and stunts antiviral signaling. SARS-CoV-2 Nsp1 binds the ribosome to inhibit translation through mRNA displacement and induces degradation of host mRNAs. Here we show that Nsp1-dependent host shutoff is conserved in diverse coronaviruses, but only Nsp1 from ß-Coronaviruses (ß-CoV) inhibits translation through ribosome binding. The C-terminal domain (CTD) of all ß-CoV Nsp1s confers high-affinity ribosome binding despite low sequence conservation. Modeling of interactions of four Nsp1s with the ribosome identified the few absolutely conserved amino acids that, together with an overall conservation in surface charge, form the ß-CoV Nsp1 ribosome-binding domain. Contrary to previous models, the Nsp1 ribosome-binding domain is an inefficient translation inhibitor. Instead, the Nsp1-CTD likely functions by recruiting Nsp1's N-terminal "effector" domain. Finally, we show that a cis-acting viral RNA element has co-evolved to fine-tune SARS-CoV-2 Nsp1 function, but does not provide similar protection against Nsp1 from related viruses. Together, our work provides new insight into the diversity and conservation of ribosome-dependent host-shutoff functions of Nsp1, knowledge that could aid future efforts in pharmacological targeting of Nsp1 from SARS-CoV-2 and related human-pathogenic ß-CoVs. Our study also exemplifies how comparing highly divergent Nsp1 variants can help to dissect the different modalities of this multi-functional viral protein.


Assuntos
Interações Hospedeiro-Patógeno , Biossíntese de Proteínas , Ribossomos , SARS-CoV-2 , Proteínas não Estruturais Virais , Humanos , Aminoácidos/química , Aminoácidos/genética , Ribossomos/metabolismo , RNA Mensageiro/genética , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Proteínas não Estruturais Virais/química , Sequência Conservada
4.
bioRxiv ; 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37333070

RESUMO

An important pathogenicity factor of SARS-CoV-2 and related coronaviruses is Nsp1, which suppresses host gene expression and stunts antiviral signaling. SARS-CoV-2 Nsp1 binds the ribosome to inhibit translation through mRNA displacement and induces degradation of host mRNAs through an unknown mechanism. Here we show that Nsp1-dependent host shutoff is conserved in diverse coronaviruses, but only Nsp1 from ß-CoV inhibits translation through ribosome binding. The C-terminal domain of all ß-CoV Nsp1s confers high-affinity ribosome-binding despite low sequence conservation. Modeling of interactions of four Nsp1s to the ribosome identified few absolutely conserved amino acids that, together with an overall conservation in surface charge, form the ß-CoV Nsp1 ribosome-binding domain. Contrary to previous models, the Nsp1 ribosome-binding domain is an inefficient translation inhibitor. Instead, the Nsp1-CTD likely functions by recruiting Nsp1's N-terminal "effector" domain. Finally, we show that a viral cis -acting RNA element has co-evolved to fine-tune SARS-CoV-2 Nsp1 function, but does not provide similar protection against Nsp1 from related viruses. Together, our work provides new insight into the diversity and conservation of ribosome-dependent host-shutoff functions of Nsp1, knowledge that could aide future efforts in pharmacological targeting of Nsp1 from SARS-CoV-2, but also related human-pathogenic ß-coronaviruses. Our study also exemplifies how comparing highly divergent Nsp1 variants can help to dissect the different modalities of this multi-functional viral protein.

5.
Sports Med ; 53(1): 1-5, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35687251

RESUMO

The global health and wellness industry has an estimated value of US$4 trillion. Profits derive from heath club memberships, exercise classes, diets, supplements, alternative 'therapies', and thousands of other products and services that are purported to improve health, recovery, and/or sports performance. The industry has expanded at an alarming rate, far outstripping the capacity of federal bodies to regulate the market and protect consumer interests. As a result, many products are sold on baseless or exaggerated claims, feigned scientific legitimacy, and questionable evidence of safety and efficacy. This article is a consciousness raiser. Herein, the implications of the mismatch between extraordinary health and performance claims and the unextraordinary scientific evidence are discussed. Specifically, we explore how pseudoscience and so-called 'quick fix' interventions undermine initiatives aimed at evoking long-term behavior change, impede the ongoing pursuit of sports performance, and lead to serious downstream consequences for clinical practice. Moreover, pseudoscience in health and wellness, if left unchecked and unchallenged, may have profound implications for the reputation of exercise science as a discipline. This is a call to action to unify exercise scientists around the world to more proactively challenge baseless claims and pseudoscience in the commercial health and wellness industry. Furthermore, we must shoulder the burden of ensuring that the next generation of exercise scientists are sufficiently skilled to distinguish science from pseudoscience, and information from mis- and disinformation. Better population health, sports performance, and the very reputation of the discipline may depend on it.


Assuntos
Desempenho Atlético , Pseudociência , Humanos , Exercício Físico , Suplementos Nutricionais , Dieta
6.
Am J Ophthalmol Case Rep ; 26: 101471, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35300401

RESUMO

Purpose: To present a case of nutritional vitamin A deficiency (VAD) that caused bilateral severe dry eye symptoms and progressive visual field contraction over a 13.5-month span resulting in peripheral blindness and nyctalopia, and to document the patient's rapid visual field restoration following vitamin A therapy (VAT). Observations: A 34-year-old Haitian woman presented for a glaucoma consultation with the following symptoms in both eyes (OU): painful dry eyes, floaters, nyctalopia, and visual field contraction over eighteen months despite treatment with four anti-glaucoma medications and intraocular pressures (IOP) in the low teens OU. The glaucoma diagnosis was eliminated due to slit lamp examination and OCT imaging, which showed an absence of both optic neuropathy and secondary glaucoma features. The patient's symptoms remained consistent with VAD. The patient's visual field decline was restored with significant documented visual field improvement occurring within only 11 days, and complete visual field restoration within 5.5 months of VAT. Conclusions and Importance: Our case demonstrates the critical role of vitamin A in maintaining ocular health and visual field preservation. To our knowledge, this is the second reported case documenting a patient's visual field decline due to VAD, as well as visual field restoration following enteral VAT. As visual outcomes of VAT are significantly underreported in scientific literature, it is imperative that ophthalmologists are aware of its effects.

7.
Syst Biol ; 71(5): 1032-1044, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35041001

RESUMO

Bonytongues (Osteoglossomorpha) constitute an ancient clade of teleost fishes distributed in freshwater habitats throughout the world. The group includes well-known species such as arowanas, featherbacks, pirarucus, and the weakly electric fishes in the family Mormyridae. Their disjunct distribution, extreme morphologies, and electrolocating capabilities (Gymnarchidae and Mormyridae) have attracted much scientific interest, but a comprehensive phylogenetic framework for comparative analysis is missing, especially for the species-rich family Mormyridae. Of particular interest are disparate craniofacial morphologies among mormyrids which might constitute an exceptional model system to study convergent evolution. We present a phylogenomic analysis based on 546 exons of 179 species (out of 260), 28 out of 29 genera, and all six families of extant bonytongues. Based on a recent reassessment of the fossil record of osteoglossomorphs, we inferred dates of divergence among transcontinental clades and the major groups. The estimated ages of divergence among extant taxa (e.g., Osteoglossomorpha, Osteoglossiformes, and Mormyroidea) are older than previous reports, but most of the divergence dates obtained for clades on separate continents are too young to be explained by simple vicariance hypotheses. Biogeographic analysis of mormyrids indicates that their high species diversity in the Congo Basin is a consequence of range reductions of previously widespread ancestors and that the highest diversity of craniofacial morphologies among mormyrids originated in this basin. Special emphasis on a taxon-rich representation for mormyrids revealed pervasive misalignment between our phylogenomic results and mormyrid taxonomy due to repeated instances of convergence for extreme craniofacial morphologies. Estimation of ancestral phenotypes revealed contingent evolution of snout elongation and unique projections from the lower jaw to form the distinctive Schnauzenorgan. Synthesis of comparative analyses suggests that the remarkable craniofacial morphologies of mormyrids evolved convergently due to niche partitioning, likely enabled by interactions between their exclusive morphological and electrosensory adaptations. [Africa; ancestral state estimation; diversity; exon capture; freshwater fishes; Phylogenomics.].


Assuntos
Peixe Elétrico , Animais , Peixe Elétrico/genética , Peixes/genética , Fósseis , Água Doce , Filogenia , Língua
8.
Zookeys ; 1129: 163-196, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36761845

RESUMO

Heteromormyrus Steindachner, 1866, a genus of Mormyridae (Teleostei: Osteoglossomorpha), has been monotypic since the description of Heteromormyruspauciradiatus (Steindacher, 1866) from a single specimen. No type locality other than "Angola" was given and almost no specimens have been subsequently identified to this species. In order to investigate the relationship of this taxon to fresh specimens collected in Angola and elsewhere, whole genome paired-end sequencing of DNA extracted from the holotype specimen of Heteromormyruspauciradiatus was performed and a nearly complete mitogenome assembled from the sequences obtained. Comparison of cytochrome oxidase I and cytochrome b sequences from this mitogenome to sequences from recently collected material reveal that Heteromormyruspauciradiatus is closely related to specimens identified as Hippopotamyrusansorgii (Boulenger, 1905), Hippopotamyrusszaboi Kramer, van der Bank & Wink, 2004, Hippopotamyruslongilateralis Kramer & Swartz, 2010, as well as to several undescribed forms from subequatorial Africa collectively referred to in the literature as the "Hippopotamyrusansorgii species complex" and colloquially known as "slender stonebashers." Previous molecular phylogenetic work has shown that these species are not close relatives of Hippopotamyruscastor Pappenheim, 1906, the type species of genus Hippopotamyrus Pappenheim, 1906 from Cameroon, and are thus misclassified. Hippopotamyrusansorgii species complex taxa and another species shown to have been misclassified, Paramormyropstavernei (Poll, 1972), are placed in genus Heteromormyrus and one genetic lineage from the Kwanza and Lucala rivers of Angola are identified as conspecific Heteromormyruspauciradiatus. Three additional new combinations and a synonymy in Mormyridae are introduced. The morphological characteristics and geographical distribution of the genus Heteromormyrus are reviewed. The electric organ discharges (EODs) of Heteromormyrus species are to be treated in a separate study.

9.
Artigo em Inglês | MEDLINE | ID: mdl-35010566

RESUMO

Background: Research in sport, military, and aerospace populations has shown that mental fatigue may impair cognitive performance. The effect of nutritional interventions that may mitigate such negative effects has been investigated. This systematic review and meta-analysis aimed to quantify the effects of nutritional interventions on cognitive domains often measured in mental fatigue research. Methods: A systematic search for articles was conducted using key terms relevant to mental fatigue in sport, military, and aerospace populations. Two reviewers screened 11,495 abstracts and 125 full texts. A meta-analysis was conducted whereby effect sizes were calculated using subgroups for nutritional intervention and cognitive domains. Results: Fourteen studies were included in the meta-analysis. The consumption of energy drinks was found to have a small positive effect on reaction time, whilst the use of beta-alanine, carbohydrate, and caffeine had no effect. Carbohydrate and caffeine use had no effect on accuracy. Conclusions: The results of this meta-analysis suggest that consuming energy drinks may improve reaction time. The lack of effect observed for other nutritional interventions is likely due to differences in the type, timing, dosage, and form of administration. More rigorous randomized controlled trials related to the effect of nutrition interventions before, during, and after induced mental fatigue are required.


Assuntos
Militares , Esportes , Cafeína , Humanos , Fadiga Mental , Tempo de Reação
10.
Database (Oxford) ; 20202020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32761142

RESUMO

The National Center for Biotechnology Information (NCBI) Taxonomy includes organism names and classifications for every sequence in the nucleotide and protein sequence databases of the International Nucleotide Sequence Database Collaboration. Since the last review of this resource in 2012, it has undergone several improvements. Most notable is the shift from a single SQL database to a series of linked databases tied to a framework of data called NameBank. This means that relations among data elements can be adjusted in more detail, resulting in expanded annotation of synonyms, the ability to flag names with specific nomenclatural properties, enhanced tracking of publications tied to names and improved annotation of scientific authorities and types. Additionally, practices utilized by NCBI Taxonomy curators specific to major taxonomic groups are described, terms peculiar to NCBI Taxonomy are explained, external resources are acknowledged and updates to tools and other resources are documented. Database URL: https://www.ncbi.nlm.nih.gov/taxonomy.


Assuntos
Classificação , Sistemas de Gerenciamento de Base de Dados , Bases de Dados Genéticas , Animais , Bactérias/genética , Humanos , National Library of Medicine (U.S.) , Plantas/genética , Estados Unidos , Vírus/genética
11.
Front Hum Neurosci ; 13: 278, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474845

RESUMO

The elite sports environment provides a unique setting for studying human performance, where both cognitive and physical demands are high. Successful performance in sport is contingent upon key cognitive skills such as attention, perception, working memory and decision-making. The demands of competitive sport also increase loading on the central nervous system (CNS). Neuroimaging methods such as functional magnetic resonance imaging (fMRI), functional near infrared spectroscopy (fNIRS) and electroencephalography (EEG) offer the potential to investigate the cognitive demands of sport, neuroplasticity of athletes, and biofeedback training. However, practical and technical limitations of these methods have generally limited their use to laboratory-based studies of athletes during simulated sporting tasks. This review article, provides a brief overview of research that has applied neuroimaging technology to study various aspects of cognitive function during sports performance in athletes, alternative methods for measuring CNS loading [e.g., direct current (DC) potential], possible solutions and avenues of focus for future neuroergonomics research in sport.

12.
Front Physiol ; 9: 743, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30002629

RESUMO

The commercial market for technologies to monitor and improve personal health and sports performance is ever expanding. A wide range of smart watches, bands, garments, and patches with embedded sensors, small portable devices and mobile applications now exist to record and provide users with feedback on many different physical performance variables. These variables include cardiorespiratory function, movement patterns, sweat analysis, tissue oxygenation, sleep, emotional state, and changes in cognitive function following concussion. In this review, we have summarized the features and evaluated the characteristics of a cross-section of technologies for health and sports performance according to what the technology is claimed to do, whether it has been validated and is reliable, and if it is suitable for general consumer use. Consumers who are choosing new technology should consider whether it (1) produces desirable (or non-desirable) outcomes, (2) has been developed based on real-world need, and (3) has been tested and proven effective in applied studies in different settings. Among the technologies included in this review, more than half have not been validated through independent research. Only 5% of the technologies have been formally validated. Around 10% of technologies have been developed for and used in research. The value of such technologies for consumer use is debatable, however, because they may require extra time to set up and interpret the data they produce. Looking to the future, the rapidly expanding market of health and sports performance technology has much to offer consumers. To create a competitive advantage, companies producing health and performance technologies should consult with consumers to identify real-world need, and invest in research to prove the effectiveness of their products. To get the best value, consumers should carefully select such products, not only based on their personal needs, but also according to the strength of supporting evidence and effectiveness of the products.

14.
J Am Osteopath Assoc ; 116(7): 440-50, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27367949

RESUMO

CONTEXT: Restless legs syndrome (RLS) treatments have included medications with many adverse effects and limited utility. A noninvasive device would potentially have extensive use where RLS medications may not be appropriate, such as in pregnant or breastfeeding women, people with mild RLS, people who operate machinery or drive occupationally, people with severely impaired renal function, or people who are taking medications contraindicated with RLS medications. OBJECTIVE: To assess the efficacy and safety of a device that produces targeted pressure on the abductor hallucis and the flexor hallucis brevis muscles to reduce the symptoms of moderate to severe RLS, and to compare the current findings with findings from studies of ropinirole use in patients with primary RLS. METHODS: This 8-week single-arm, open-label, clinical trial with a repeated measures design was conducted between April 2009 and August 2012 in 2 offices in Erie, Pennsylvania. Adults with moderate to severe primary RLS were recruited for the study. Mean (SD) follow-up was 15.6 (6) months. Patients wore RLS devices (1 on each foot) for set periods intermittently throughout the course of the study. The primary end point was mean change in the International Restless Legs Syndrome Study Group (IRLSSG) Rating Scale from baseline to day 56, and the secondary measure was the Clinical Global Impression scale. A meta-analysis was used to compare the RLS device findings with the findings of 3 historic studies of ropinirole vs placebo. The demographics, disease severity, inclusion and exclusion criteria, and assessment tools were similar among the 4 studies. RESULTS: Thirty patients (22 women, 8 men; mean age, 51.5 years [range, 30-75 years]) participated in the study. Change in mean (SD) IRLSSG score was significantly greater for the RLS device (17.22 [6.16]; P<.001) compared with the ropinirole vs placebo findings (12 [0.86] vs 8.9 [0.86], respectively; P<.05). Sleep loss significantly decreased from 119.5 (61.6) minutes to 22.1 (31.1) minutes per night (P<.001). Global Improvement Scale scores indicated significantly greater improvement with the RLS device compared with ropinirole (27 of 30 [90%] vs 293 of 464 [63%], respectively; P<.05). Mild, transient adverse effects of the device (eg, pain, paresthesia) were reported, but these effects were relieved by loosening the straps. The RLS device demonstrated none of the adverse effects associated with current dopamine agonist therapy, such as augmentation, tolerance, rebound, somnolence, and nausea. CONCLUSION: Producing targeted pressure on the abductor hallucis and flexor hallucis brevis muscles with an external RLS device reduced the symptoms of moderate to severe primary RLS without the adverse effects of medication therapy. (ClinicalTrials.gov number NCT02386423.) J Am Osteopath Assoc.


Assuntos
Agonistas de Dopamina/uso terapêutico , Indóis/uso terapêutico , Pressão , Síndrome das Pernas Inquietas/terapia , Adulto , Idoso , Agonistas de Dopamina/efeitos adversos , Tolerância a Medicamentos , Feminino , , Humanos , Indóis/efeitos adversos , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Músculo Esquelético , Efeito Placebo , Síndrome das Pernas Inquietas/tratamento farmacológico , Índice de Gravidade de Doença
15.
Zookeys ; (561): 117-50, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27006619

RESUMO

We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new species. Cryptomyrus, new genus, is readily distinguished from all other mormyrid genera by a combination of features of squamation, morphometrics, and dental attributes. Cryptomyrus ogoouensis, new species, is differentiated from its single congener, Cryptomyrus ona, new species, by the possession of an anal-fin origin located well in advance of the dorsal fin, a narrow caudal peduncle and caudal-fin lobes nearly as long as the peduncle. In Cryptomyrus ona, the anal-fin origin is located only slightly in advance of the dorsal fin, the caudal peduncle is deep and the caudal-fin lobes considerably shorter than the peduncle. Continued discovery of new taxa within the "Lower Guinea Clade" of Mormyridae highlights the incompleteness of our knowledge of fish diversity in West-Central Africa. We present a revised key to the mormyrid genera of Lower Guinea.


RésuméNous avons démontré avec des marqueurs mitochondriaux et nucléaires que trois spécimens de poissons mormyridés faiblement électriques, collectés à trois localités au Gabon sur une période de 13 ans, forment une lignée inconnue au sein de la sous famille des Mormyrinae dont nous avons déterminé la position phylogénétique. Nous décrivons un nouveau genre et deux nouvelles espèces pour ces trois spécimens. Cryptomyrus, nouveau genre, se distingue des autres genres de mormyridés par une combinaison de caractères de l'écaillure, morphométriques, et dentaires. Cryptomyrus ogoouensis, nouvelle espèce, se distingue de sa seule espèce congénérique par sa nageoire anale qui commence nettement en avant de sa nageoire dorsale, son pédoncule caudal gracile et les lobes de sa nageoire caudale pratiquement aussi longs que son pédoncule caudal. Chez Cryptomyrus ona, nouvelle espèce, la nageoire anale commence légèrement en avant de l'origine de la nageoire dorsale, le pédoncule caudal est large, et les lobes de la nageoire caudale sont plus courts que le pédoncule caudal. La découverte ininterrompue de nouveaux taxa dans le «clade de basse Guinée¼ des Mormyridae illustre notre connaissance incomplète de la diversité des poissons de l'ouest de l'Afrique centrale. Nous présentons une clé révisée des genres de Mormyridae de basse Guinée.

16.
Zootaxa ; 3962: 226-34, 2015 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-26249388

RESUMO

A new species of a small cyprinid fish, Metzia parva sp. nov., is described here based on specimens collected from a tributary of Hongshui-He River in the Pearl River basin at Anyang Town, Du'an County, Guangxi Province, south China. It differs from congeners in having a smaller body with a standard length of 48.3-57.7 mm (vs. 58.3-151.4 mm in other species); a complete lateral line (although some specimens show interruptions on the ventral margin above the anal-fin); 12-14 branched anal-fin rays (vs. 10-11 or 15-20); 10 branched pectoral-fin rays (vs. 11-16); 6 branched pelvic-fin rays (vs. 7-9); a longer caudal peduncle (17.8-21.7% vs. 14.8-17.4% SL); a shorter preanal length (60.9-66.0% vs. 69.0-73.0% SL) and an obviously larger interorbital width (28.4-33.0% vs. 20.2-24.7% of head length). While Metzia parva shares a lateral black stripe from the gill opening to the caudal-fin base with M. formosae, the new species can be distinguished from M. formosae by a deeper head (16.4-19.2% vs. 13.3-15.7% SL) and a longer anal fin (15.4-18.9% vs. 10.0-13.6% SL) in addition to the diagnostic characters above. Kimura's 2-parameter genetic distance between the two species is 6.6% for the barcoding region of the mitochondrial COI gene and 7.3% across the complete mitochondrial genome.


Assuntos
Cyprinidae/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , China , Cyprinidae/anatomia & histologia , Cyprinidae/crescimento & desenvolvimento , Ecossistema , Feminino , Masculino , Tamanho do Órgão
17.
ACS Nano ; 9(4): 4379-89, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25785517

RESUMO

Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating and stripping processes is needed to enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) to image the first few cycles of lithium electrodeposition/dissolution in liquid aprotic electrolyte at submicron resolution. Cycling at current densities from 1 to 25 mA/cm(2) leads to variations in grain structure, with higher current densities giving a more needle-like, higher surface area deposit. The effect of the electron beam was explored, and it was found that, even with minimal beam exposure, beam-induced surface film formation could alter the Li microstructure. The electrochemical dissolution was seen to initiate from isolated points on grains rather than uniformly across the Li surface, due to the stabilizing solid electrolyte interphase surface film. We discuss the implications for operando STEM liquid-cell imaging and Li-battery applications.

19.
Zootaxa ; 3841(2): 257-70, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-25082039

RESUMO

Paraqianlabeo, new genus, is described from the Chishui-He and Wu-Jiang rivers of the Yangtze River basin in Guizhou Province, South China. This new genus is distinguished from all other labeonine genera by a combination of morphological and molecular evidence. It is distinguished from all other Asian garrains by a unique oromandibular morphology; i.e., an arched, wide, rudimentary sucker formed by raised front and lateral margins of lower lip, postlabial groove and mental groove between middle and lateral lobes of lower lip chevron-shaped; anteroventral margin of rostral cap arched, thin and papillose; rostral cap not overlying upper lip, upper lip connected with lower lip around corners of mouth; well developed upper lip free from upper jaw; lower lip divided into two lateral fleshy lobes and one central plate, these two lateral fleshy lobes small and short, median lobe of lower lip large; anterior and anterolateral edges of upper and lower lip finely papillose; shallow, straight groove between lower lip and lower jaw; lower jaw bears thin, cornified cutting edge. Additionally, scales on mid-ventral region from pectoral fins to pelvic fins subcutaneous and half-hidden; dorsal fin with 3 simple and 7½-8 branched rays. Paraqianlabeo lineatus, new species, type species of this genus, has longitudinal dark stripe along side of body. Analyses of mitochondrial DNA data indicate that this new genus forms a highly diverged lineage within the Garraina group of Labeoninae. 


Assuntos
Cyprinidae/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , China , Cyprinidae/anatomia & histologia , Cyprinidae/genética , Cyprinidae/crescimento & desenvolvimento , DNA Mitocondrial/genética , Feminino , Masculino , Dados de Sequência Molecular , Tamanho do Órgão , Filogenia
20.
Zookeys ; (400): 43-65, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24843255

RESUMO

A specimen of the African weakly electric fish genus Petrocephalus (Osteoglossomorpha, Mormyridae) collected in the Congo River at Yangambi, Orientale Province, Democratic Republic of Congo, is described as a new species. Petrocephalus boboto sp. n. can be distinguished from other Central African species of Petrocephalus by a combination of the following characteristics: three distinct black spots on the body, one at the origin of the pectoral fin, one at the origin of the caudal fin and one below the anterior base of the dorsal fin; Nakenrosette and Khelrosette electroreceptor clusters distinct on head but Augenrosette cluster reduced in size; 23 branched dorsal rays, 34 branched anal rays, and electric organ discharge waveform triphasic. Petrocephalus boboto sp. n. most closely resembles the holotype of Petrocephalus binotatus but is easily distinguished from it by its smaller mouth. A comparative molecular analysis including 21 other Petrocephalus species shows Petrocephalus boboto sp. n. to be genetically distinctive and to represent a deep lineage in the genus. Two specimens of Petrocephalus collected at Yangambi are morphologically similar and genetically closely related to specimens previously assigned to Petrocephalus binotatus, collected in the northwestern Congo River basin within Odzala-Kokua National Park, Republic of the Congo. This prompts us to formally describe a new species from these collections, Petrocephalus arnegardi sp. n., that, although similar to the holotype of Petrocephalus binotatus, can be distinguished from it by its smaller mouth and shorter interorbital width.


RésuméUn spécimen de poissons africains à faible décharge électrique du genre Petrocephalus (Osteoglossomorpha, Mormyridae) collecté dans le fleuve Congo à Yangambi, Province Orientale, République Démocratique du Congo, est décrit comme une nouvelle espèce. Petrocephalus bobotosp. n. peut-être distinguée des autres espèces de Petrocephalus d'Afrique Centrale par la présence de trois distinctes taches noires, l'une à la base des nageoires pectorales, la seconde à la base de la nageoire caudale et la troisième sur chacun des flancs, juste en dessous des premiers rayons de la nageoire dorsale; présence bien visible de deux rosettes électroréceptives sur la tête (Nakenrosette et Khelrosette), la troisième rosette (Augenrosette) est de taille réduite; 23 rayons branchus à la nageoire dorsale et 34 rayons à la nageoire anale; et décharge électrique triphasique. Petrocephalus bobotosp. n. ressemble le plus à l'holotype de Petrocephalus binotatus mais s'en distingue par une bouche nettement plus petite. Une analyse génétique confirme la distinction de Petrocephalus boboto sp. n. parmi un échantillon de 21 espèces. Cette analyse montre également que cette nouvelle espèce représente une lignée distincte de Petrocephalus. Deux autres spécimens de Petrocephalus collectés à Yangambi sont morphologiquement et génétiquement proches de spécimens auparavant identifiés comme appartenant à Petrocephalus binotatus, collectés dans le Parc National d'Odzala-Kokua, bassin du Congo, République du Congo. Ceci nous amène à les décrire comme une nouvelle espèce, Petrocephalus arnegardisp. n. qui peut-être distinguée de l'holotype de Petrocephalus binotatus par une bouche plus petite et un espace inter-orbitaire plus court.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA