Polarization Conforms Performance Variability in Amorphous Electrodeposited Iridium Oxide pH Sensors: A Thorough Surface Chemistry Investigation.

Electrodeposited amorphous hydrated iridium oxide (IrOx) is a promising material for pH sensing due to its high sensitivity and the ease of fabrication. However, durability and variability continue to restrict the sensor's effectiveness. Variation in probe films can be seen in both performance and fabrication, but it has been found that performance variation can be controlled with potentiostatic conditioning (PC). To make proper use of this technique, the morphological and chemical changes affecting the conditioning process must be understood. Here, a thorough study of this material, after undergoing PC in a pH-sensing-relevant potential regime, was conducted by voltammetry, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Fitting of XPS data was performed, guided by raw trends in survey scans, core orbitals, and valence spectra, both XPS and UPS. The findings indicate that the PC process can repeatably control and conform performance and surface bonding to desired calibrations and distributions, respectively; PC was able to reduce sensitivity and offset ranges to as low as ±0.7 mV/pH and ±0.008 V, respectively, and repeat bonding distributions over ~2 months of sample preparation. Both Ir/O atomic ratios (shifting from 4:1 to over 4.5:1) and fitted components assigned hydroxide or oxide states based on the literature (low-voltage spectra being almost entirely with suggested hydroxide components, and high-voltage spectra almost entirely with suggested oxide components) trend across the polarization range. Self-consistent valence, core orbital, and survey quantitative trends point to a likely mechanism of ligand conversion from hydroxide to oxide, suggesting that the conditioning process enforces specific state mixtures that include both theoretical Ir(III) and Ir(IV) species, and raising the conditioning potential alters the surface species from an assumed mixture of Ir species to more oxidized Ir species.

A tiered approach to investigate the inhalation toxicity of cobalt substances. Tier 1: Bioaccessibility testing.

Bioelution tests measure in vitro the release of metal ion in surrogate physiological conditions (termed "bioaccessibility") and estimate the potential bioavailability relative to that of a known reference metal substance. Bioaccessibility of cobalt ion from twelve cobalt substances was tested in three artificial lung fluids (interstitial, alveolar and lysosomal) to gather information about the substances' fate and potential bioavailability in the respiratory tract after inhalation. The results can be used as one line of evidence to support grouping and read-across for substances lacking in vivo data, and where in vivo testing is not readily justifiable. Strong differences were observed in the dissolution behaviour of the substances in the different fluids, with the cobalt substances generally being less soluble in neutral pH fluids and more soluble in the acidic pH fluid. The resulting database, presented with its strengths and limitations, was used to support the formulation of an initial grouping of these cobalt substances into three categories.

Fabrication of Highly Sensitive Pt-black Electrochemical Sensors for GABA Detection.

GABA (Gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system of mammals. It is known to be related with various neurological disorders. GABA plays a crucial role in normal neuronal activity, information processing and plasticity, and neuronal network synchronization. To date, microdialysis has been widely used to monitor the level of GABA but the temporal and spatial resolution is limited. Besides, electrochemical sensors for neurotransmitter measurement, having high temporal and spatial resolution, overcome this problem. Here, using a cost-effective method of electrodeposition of platinum black (Pt-black), a highly sensitive, GABA specific, amperometric electrochemical sensor is fabricated. Nanostructured Pt-black increases the active surface area of the electrode contributing to higher sensitivity. Along with that, a self-referencing site and an exclusion layer are integrated to increase the selectivity and the signal-to-noise ratio (SNR) of the biosensor. This provides a prototype for a highly sensitive GABA sensor that could later be used to study various neurological disorders related to GABA concentrations.Clinical Relevance- This electrochemical sensor allows real-time monitoring of major inhibitory neurotransmitter (GABA) with high sensitivity which can be used for studying various neurological disorders.

A Fluidics-Based Biosensor to Detect and Characterize Inhibition Patterns of Organophosphate to Acetylcholinesterase in Food Materials.

A chip-based electrochemical biosensor is developed herein for the detection of organophosphate (OP) in food materials. The principle of the sensing platform is based on the inhibition of dimethoate (DMT), a typical OP that specifically inhibits acetylcholinesterase (AChE) activity. Carbon nanotube-modified gold electrodes functionalized with polydiallyldimethylammonium chloride (PDDA) and oxidized nanocellulose (NC) were investigated for the sensing of OP, yielding high sensitivity. Compared with noncovalent adsorption and deposition in bovine serum albumin, bioconjugation with lysine side chain activation allowed the enzyme to be stable over three weeks at room temperature. The total amount of AChE was quantified, whose activity inhibition was highly linear with respect to DMT concentration. Increased incubation times and/or DMT concentration decreased current flow. The composite electrode showed a sensitivity 4.8-times higher than that of the bare gold electrode. The biosensor was challenged with organophosphate-spiked food samples and showed a limit of detection (LOD) of DMT at 4.1 nM, with a limit of quantification (LOQ) at 12.6 nM, in the linear range of 10 nM to 1000 nM. Such performance infers significant potential for the use of this system in the detection of organophosphates in real samples.

Cardiac tissue engineering: state-of-the-art methods and outlook.

The purpose of this review is to assess the state-of-the-art fabrication methods, advances in genome editing, and the use of machine learning to shape the prospective growth in cardiac tissue engineering. Those interdisciplinary emerging innovations would move forward basic research in this field and their clinical applications. The long-entrenched challenges in this field could be addressed by novel 3-dimensional (3D) scaffold substrates for cardiomyocyte (CM) growth and maturation. Stem cell-based therapy through genome editing techniques can repair gene mutation, control better maturation of CMs or even reveal its molecular clock. Finally, machine learning and precision control for improvements of the construct fabrication process and optimization in tissue-specific clonal selections with an outlook of cardiac tissue engineering are also presented.

Retention of Ancestral Genetic Variation Across Life-Stages of an Endangered, Long-Lived Iteroparous Fish.

As with many endangered, long-lived iteroparous fishes, survival of razorback sucker depends on a management strategy that circumvents recruitment failure that results from predation by non-native fishes. In Lake Mohave, AZ-NV, management of razorback sucker centers on capture of larvae spawned in the lake, rearing them in off-channel habitats, and subsequent release ("repatriation") to the lake when adults are sufficiently large to resist predation. The effects of this strategy on genetic diversity, however, remained uncertain. After correction for differences in sample size among groups, metrics of mitochondrial DNA (mtDNA; number of haplotypes, N H , and haplotype diversity, H D ) and microsatellite (number of alleles, N A , and expected heterozygosity, H E ) diversity did not differ significantly between annual samples of repatriated adults and larval year-classes or among pooled samples of repatriated adults, larvae, and wild fish. These findings indicate that the current management program thus far maintained historical genetic variation of razorback sucker in the lake. Because effective population size, N e , is closely tied to the small census population size (N c = ~1500-3000) of razorback sucker in Lake Mohave, this population will remain at risk from genetic, as well as demographic risk of extinction unless N c is increased substantially.

Population Structure in the Roundtail Chub (Gila robusta Complex) of the Gila River Basin as Determined by Microsatellites: Evolutionary and Conservation Implications.

Ten microsatellite loci were characterized for 34 locations from roundtail chub (Gila robusta complex) to better resolve patterns of genetic variation among local populations in the lower Colorado River basin. This group has had a complex taxonomic history and previous molecular analyses failed to identify species diagnostic molecular markers. Our results supported previous molecular studies based on allozymes and DNA sequences, which found that most genetic variance was explained by differences among local populations. Samples from most localities were so divergent species-level diagnostic markers were not found. Some geographic samples were discordant with current taxonomy due to admixture or misidentification; therefore, additional morphological studies are necessary. Differences in spatial genetic structure were consistent with differences in connectivity of stream habitats, with the typically mainstem species, G. robusta, exhibiting greater genetic connectedness within the Gila River drainage. No species exhibited strong isolation by distance over the entire stream network, but the two species typically found in headwaters, G. nigra and G. intermedia, exhibited greater than expected genetic similarity between geographically proximate populations, and usually clustered with individuals from the same geographic location and/or sub-basin. These results highlight the significance of microevolutionary processes and importance of maintaining local populations to maximize evolutionary potential for this complex. Augmentation stocking as a conservation management strategy should only occur under extreme circumstances, and potential source populations should be geographically proximate stocks of the same species, especially for the headwater forms.

First record of the genus Caenophanes Foerster (Hymenoptera: Braconidae: Doryctinae) for America north of Mexico with a description of a new species from Wyoming USA .

The first species of Caenophanes Foerster recorded from America north of Mexico is described: Caenophanes harlowi Haimowitz and Marsh, and a key to distinguish the two described New World species is provided. We discuss evidence that suggests that Caenophanes is likely to have cosmopolitan distribution and may be more common than might be anticipated from the current number of described species.

Time-series analysis reveals genetic responses to intensive management of razorback sucker (Xyrauchen texanus).

Time-series analysis is used widely in ecology to study complex phenomena and may have considerable potential to clarify relationships of genetic and demographic processes in natural and exploited populations. We explored the utility of this approach to evaluate population responses to management in razorback sucker, a long-lived and fecund, but declining freshwater fish species. A core population in Lake Mohave (Arizona-Nevada, USA) has experienced no natural recruitment for decades and is maintained by harvesting naturally produced larvae from the lake, rearing them in protective custody, and repatriating them at sizes less vulnerable to predation. Analyses of mtDNA and 15 microsatellites characterized for sequential larval cohorts collected over a 15-year time series revealed no changes in geographic structuring but indicated significant increase in mtDNA diversity for the entire population over time. Likewise, ratios of annual effective breeders to annual census size (N b /N a) increased significantly despite sevenfold reduction of N a. These results indicated that conservation actions diminished near-term extinction risk due to genetic factors and should now focus on increasing numbers of fish in Lake Mohave to ameliorate longer-term risks. More generally, time-series analysis permitted robust testing of trends in genetic diversity, despite low precision of some metrics.

The Doryctinae (Braconidae) of Costa Rica: genera and species of the tribe Heterospilini.

A comprehensive taxonomic study is presented for the four genera and 286 species of the doryctine tribe Heterospilini occurring in Costa Rica. The tribe is represented almost entirely by the 280 species of the genus Heterospilus Haliday. Keys for identification of the genera and species are provided and the genera and species are described and illustrated. An interactive key to the species of Heterospilus also was prepared using Lucid Builder. The following new genus and species are described from Costa Rica: Paraheterospilus gen. n., P. ceciliaensis sp. n., P. eumekus sp. n., P. wilbotgardus sp. n., Heterospilus achi sp. n., H. achterbergi sp. n., H. aesculapius sp. n., H. agujas sp. n., H. agujasensis sp. n., H. alajuelus sp. n., H. albocoxalis sp. n., H. alejandroi sp. n., H. amuzgo sp. n., H. angelicae sp. n., H. angustus sp. n., H. aphrodite sp. n., H. apollo sp. n., H. arawak sp. n., H. areolatus sp. n., H. artemis sp. n., H. athena sp. n., H. attraholucus sp. n., H. aubreyae sp. n., H. austini sp. n., H. azofeifai sp. n., H. bacchus sp. n., H. barbalhoae sp. n., H. bennetti sp. n., H. bicolor sp. n., H. boharti sp. n., H. borucas sp. n., H. braeti sp. n., H. brethesi sp. n., H. breviarius sp. n., H. brevicornus sp. n., H. bribri sp. n., H. brullei sp. n., H. bruesi sp. n., H. cabecares sp. n., H. cacaoensis sp. n., H. cachiensis sp. n., H. cameroni sp. n., H. cangrejaensis sp. n., H. careonotaulus sp. n., H. caritus sp. n., H. carolinae sp. n., H. cartagoensis sp. n., H. catiensis sp. n., H. catorce sp. n., H. cero sp. n., H. chaoi sp. n., H. chilamatensis sp. n., H. chocho sp. n., H. chorotegus sp. n., H. chorti sp. n., H. cinco sp. n., H. cocopa sp. n., H. colliletus sp. n., H. colonensis sp. n., H. complanatus sp. n., H. conservatus sp. n., H. cora sp. n., H. corcovado sp. n., H. corrugatus sp. n., H. costaricensis sp. n., H. cressoni sp. n., H. cuatro sp. n., H. curtisi sp. n., H. cushmani sp. n., H. dani sp. n., H. demeter sp. n., H. dianae sp. n., H. diecinueve sp. n., H. dieciocho sp. n., H. dieciseis sp. n., H. diecisiete sp. n., H. diez sp. n., H. doce sp. n., H. dos sp. n., H. dulcus sp. n., H. eberhardi sp. n., H. ektorincon sp. n., H. emilius sp. n., H. empalmensis sp. n., H. enderleini sp. n., H. escazuensis sp. n., H. fahringeri sp. n., H. fischeri sp. n., H. flavidus sp. n., H. flavisoma sp. n., H. flavostigmus sp. n., H. foersteri sp. n., H. fonsecai sp. n., H. fournieri sp. n., H. gahani sp. n., H. garifuna sp. n., H. gauldi sp. n., H. golfodulcensis sp. n., H. gouleti sp. n., H. granulatus sp. n., H. grisselli sp. n., H. guanacastensis sp. n., H. guapilensis sp. n., H. hachaensis sp. n., H. halidayi sp. n., H. hansoni sp. n., H. hansonorum sp. n., H. haplocarinus sp. n., H. hedqvisti sp. n., H. hera sp. n., H. heredius sp. n., H. hespenheidei sp. n., H. holleyae sp. n., H. huddlestoni sp. n., H. huetares sp. n., H. hypermekus sp. n., H. itza sp. n., H. ixcatec sp. n., H. ixil sp. n., H. jabillosensis sp. n., H. jakaltek sp. n., H. janzeni sp. n., H. jennieae sp. n., H. jonmarshi sp. n., H. jupiter sp. n., H. kellieae sp. n., H. kiefferi sp. n., H. kikapu sp. n., H. kulai sp. n., H. kuna sp. n., H. lapierrei sp. n., H. lasalturus sp. n., H. laselvus sp. n., H. leenderti sp. n., H. leioenopus sp. n., H. leiponotaulus sp. n., H. lenca sp. n., H. levis sp. n., H. leviscutum sp. n., H. levitergum sp. n., H. limonensis sp. n., H. longinoi sp. n., H. longisulcus sp. n., H. longius sp. n., H. luteogaster sp. n., H. luteoscutum sp. n., H. luteus sp. n., H. macrocarinus sp. n., H. macrocaudatus sp. n., H. magnus sp. n., H. malaisei sp. n., H. mam sp. n., H. maritzaensis sp. n., H. mars sp. n., H. masneri sp. n., H. masoni sp. n., H. mellosus sp. n., H. menkei sp. n., H. mercury sp. n., H. milleri sp. n., H. miskito sp. n., H. mixtec sp. n., H. monteverde sp. n., H. mopanmaya sp. n., H. muertensis sp. n., H. muesebecki sp. n., H. nahua sp. n., H. neesi sp. n., H. nemestrinus sp. n., H. nephilim sp. n., H. nephus sp. n., H. nigracapitus sp. n., H. nigragonatus sp. n., H. nigricoxus sp. n., H. nixoni sp. n., H. noyesi sp. n., H. nueve sp. n., H. nunesi sp. n., H. once sp. n., H. orbitus sp. n., H. orosi sp. n., H. paloverde sp. n., H. pappi sp. n., H. parkeri sp. n., H. parvus sp. n., H. pech sp. n., H. penosa sp. n., H. petiolatus sp. n., H. petralbus sp. n., H. phaeocoxus sp. n., H. phaeoskelus sp. n., H. pharkidodus sp. n., H. phytorius sp. n., H. pitillaensis sp. n., H. poqomchi sp. n., H. poqomom sp. n., H. puertoviejoensis sp. n., H. puntarensis sp. n., H. qanjobal sp. n., H. quickei sp. n., H. quitirrisi sp. n., H. racostica sp. n., H. rama sp. n., H. ramirezi sp. n., H. ratzeburgi sp. n., H. reagani sp. n., H. reinhardi sp. n., H. retheospilus sp. n., H. rhabdotus sp. n., H. ricacosta sp. n., H. rinconensis sp. n., H. robbieae sp. n., H. rohweri sp. n., H. rojasi sp. n., H. romani sp. n., H. rugosus sp. n., H. sabrinae sp. n., H. saminae sp. n., H. sanjosensis sp. n., H. santarosensis sp. n., H. sanvitoensis sp. n., H. saturn sp. n., H. seis sp. n., H. sergeyi sp. n., H. sharkeyi sp. n., H. shawi sp. n., H. shenefelti sp. n., H. shonan sp. n., H. siete sp. n., H. similis sp. n., H. sinuatus sp. n., H. smithi sp. n., H. spiloheterus sp. n., H. staryi sp. n., H. stelfoxi sp. n., H. strazanaci sp. n., H. sumo sp. n., H. szepligeti sp. n., H. terrabas sp. n., H. thereospilus sp. n., H. tobiasi sp. n., H. tolupan sp. n., H. townesi sp. n., H. trece sp. n., H. tres sp. n., H. tricolor sp. n., H. trienta sp. n., H. tuberculatus sp. n., H. turrialbaensis sp. n., H. tzutujil sp. n., H. ugaldei sp. n., H. uno sp. n., H. variabilis sp. n., H. veinte sp. n., H. veintidos sp. n., H. veintitres sp. n., H. veintiuno sp. n., H. vierecki sp. n., H. villegasi sp. n., H. vittatus sp. n., H. vulcanus sp. n., H. wahli sp. n., H. warreni sp. n., H. washingtoni sp. n., H. wesmaeli sp. n., H. whartoni sp. n., H. whitfieldi sp. n., H. wildi sp. n., H. wilkinsoni sp. n., H. wrightae sp. n., H. xanthus sp. n., H. xerxes sp. n., H. xinca sp. n., H. yaqui sp. n., H. ypsilon sp. n., H. zapotec sp. n., H. zeus sp. n., H. zitaniae sp. n., H. zoque sp. n., H. zunigai sp. n., H. zurquiensis sp. n. One new combination is proposed, Pioscelus costaricensis (Marsh) comb. n.

Fast-evolving homoplastic traits are best for species identification in a group of neotropical wasps.

Biological characters can be employed for both taxonomy and phylogenetics, but is conscripting characters for double duty a good idea? We explore the evolution of characters designed for taxonomic diagnosis in Costa Rican heterospiline wasps, a hyperdiverse lineage of parasitoid Braconidae, by mapping them to a robust multi-locus molecular phylogeny. We discover a strong positive relationship between the amount of evolutionary change a character undergoes and how broadly useful the characters are in the context of an interactive identification key--e.g., how evenly the character states are distributed among taxa. The empirical finding that fast characters are the most useful for species identification supports the idea that characters designed for taxonomic diagnoses are likely to underperform--or be positively misleading--in phylogenetic analyses.

Revision of North American Aleiodes (Part 9): the pallidator (Thunberg) species-group with description of two new species (Hymenoptera: Braconidae, Rogadinae).

The Aleiodes pallidator species-group is defined, and an identification key is provided for the five species known to occur in the U.S.A. and Canada. Two new species are described: Aleiodes martini Shaw and Marsh, from Florida, and A. xanthoclypeus Shaw and Marsh, known from Canada and Wisconsin, and reared from Lymantriidae species including Dasychira plagiata (Walker) and Olene grisefacta (a new host record for the genus Aleiodes). Five species are illustrated, and their host associations are summarized.

Doryctopambolus Nunes & Zaldívar-Riverón (Braconidae), a new neotropical doryctine wasp genus with propodeal spines.

The new Neotropical doryctine genus Doryctopambolusgen. n. is erected to contain Doryctopambolus pilcomayensis (van Achterberg & Braet, 2004), comb. n., which was previously placed within Pambolus (Pambolinae), as well as three new species, Doryctopambolus clebschisp. n., Doryctopambolus dominicanussp. n. and Doryctopambolus sarochensissp. n. Members of this new genus are mainly characterised by the presence of at least one pair of conspicuous propodeal apico-lateral projections, which are similar to those present in all members of Pambolinae and in species of three Australasian doryctine genera. We generated DNA barcoding sequences for the three newly described species. We discuss the morphological similarity between species of the Australasian Echinodoryctes Belokobylskij, Iqbal & Austin and Doryctopambolus. A key for the described species of Doryctopambolus is provided.