Tick fauna from two locations in the Brazilian savannah.

PubMed

Szabó, Matias Pablo Juan; Olegário, Maria Marlene Martins; Santos, André Luiz Quagliatto

2007-01-01

The Cerrado is Brazil's tropical savannah, which is arguably under greater threat than the Amazon rainforest. The Cerrado Biome of tropical South America covers about 2 million km(2) and is considered a biodiversity hot spot which means that it is especially rich in endemic species and particularly threatened by human activities. The Cerrado is increasingly exposed to agricultural activities which enhance the likelihood of mixing parasites from rural, urban and wildlife areas. Information about ticks from the Cerrado biome is scarce. In this report tick species free-living, on domestic animals and on a few wild animals in two farms in the Cerrado biome (Nova Crixás and Araguapaz municipalities, Goiás State, Brazil) are described. Amblyomma cajennense was the first and Amblyomma parvum the second host-seeking tick species found. Only two other tick species were found free-living: one Amblyomma nodosum and three Amblyomma naponense nymphs. Cattle were infested with Boophilus microplus and A. cajennense. Buffalos were infested with B. microplus and A. parvum. Dogs were infested with A. cajennense, Amblyomma ovale, A. parvum and Rhipicephalus sanguineus ticks. Anocentor nitens, B. microplus, A. cajennense, and A. parvum were found on horses. Amblyomma auricularium were found attached to nine-banded armadillos and Amblyomma rotundatum to red-footed tortoise, cururu toads and a rattlesnake. The latter was also infested with an adult A. cajennense. No tick was found on a goat, a tropical rat snake and a yellow armadillo. Among the observations the infestation of several domestic animals with A. parvum seems be the main feature. It suggests that this species might become a pest. However, the life cycle of A. parvum in nature, as well as its disease vectoring capacity, are largely unknown. It would be important to determine if it is a species expanding its geographic range by adaptation to new hosts or if it has been maintained in high numbers at definite locations by

On the persistence of reproductive barriers in Eucalyptus: the bridging of mechanical barriers to zygote formation by F1 hybrids is counteracted by intrinsic post-zygotic incompatibilities.

PubMed

Larcombe, Matthew J; Costa E Silva, João; Tilyard, Paul; Gore, Peter; Potts, Brad M

2016-09-01

Many previous studies conclude that pre-zygotic barriers such as mechanical isolation account for most reproductive isolation between pairs of taxa. However, the inheritance and persistence of barriers such as these after the first generation of hybridization is rarely quantified, even though it is a vital consideration in understanding gene flow potential. There is an asymmetrical pre-zygotic mechanical barrier to hybridization between Eucalyptus nitens and Eucalyptus globulus, which completely prevents small-flowered E. nitens pollen from mating with large E. globulus flowers, while the reverse cross is possible. We aimed to determine the relative importance of pre- and post-zygotic barriers in preventing gene flow following secondary contact between E. nitens and E. globulus, including the inheritance of barriers in advanced-generation hybrids. Experimental crossing was used to produce outcrossed E. nitens, E. globulus and their F1, F2, BCg and BCn hybrids. The strength and inheritance of a suite of pre- and post-zygotic barriers were assessed, including 20-year survival, growth and reproductive capacity. The mechanical barrier to hybridization was lost or greatly reduced in the F1 hybrid. In contrast, intrinsic post-zygotic barriers were strong and persistent. Line-cross analysis indicated that the outbreeding depression in the hybrids was best explained by epistatic loss. The removal of strong mechanical barriers between E. nitens and E. globulus allows F1 hybrids to act as a bridge for bi-directional gene flow between these species. However, strong and persistent post-zygotic barriers exist, meaning that wherever F1 hybridization does occur, intrinsic post-zygotic barriers will be responsible for most reproductive isolation in this system. This potential transient nature of mechanical barriers to zygote formation due to additive inheritance in hybrids appears under-appreciated, and highlights the often important role that intrinsic post-mating barriers play

Eucalypt Improvement for California: Progress and Plans

Treesearch

F. Thomas Ledig

1983-01-01

Six promising eucalypt species, suitable for fiber or biomass production, have been identified with some confidence: Eucalyptus camaldulensis, E. dalrympleana, E. viminalis, E. nitens, E. globulus, and E. grandis. The Forest Service...

Resistance of green lacewing, Chrysoperla carnea Stephens to nitenpyram: Cross-resistance patterns, mechanism, stability, and realized heritability.

PubMed

Mansoor, Muhammad Mudassir; Raza, Abu Bakar Muhammad; Abbas, Naeem; Aqueel, Muhammad Anjum; Afzal, Muhammad

2017-01-01

The green lacewing, Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) is a major generalist predator employed in integrated pest management (IPM) plans for pest control on many crops. Nitenpyram, a neonicotinoid insecticide has widely been used against the sucking pests of cotton in Pakistan. Therefore, a field green lacewing strain was exposed to nitenpyram for five generations to investigate resistance evolution, cross-resistance pattern, stability, realized heritability, and mechanisms of resistance. Before starting the selection with nitenpyram, a field collected strain showed 22.08-, 23.09-, 484.69- and 602.90-fold resistance to nitenpyram, buprofezin, spinosad and acetamiprid, respectively compared with the Susceptible strain. After continuous selection for five generations (G1-G5) with nitenpyram in the laboratory, the Field strain (Niten-SEL) developed a resistance ratio of 423.95 at G6. The Niten-SEL strain at G6 showed no cross-resistance to buprofezin and acetamiprid and negative cross-resistance to spinosad compared with the Field strain (G1). For resistance stability, the Niten-SEL strain was left unexposed to any insecticide for four generations (G6-G9) and bioassay results at G10 showed that resistance to nitenpyram, buprofezin and spinosad was stable, while resistance to acetamiprid was unstable. The realized heritability values were 0.97, 0.16, 0.03, and -0.16 to nitenpyram, buprofezin, acetamiprid and spinosad, respectively, after five generations of selection. Moreover, the enzyme inhibitors (PBO or DEF) significantly decreased the nitenpyram resistance in the resistant strain, suggesting that resistance was due to microsomal oxidases and esterases. These results are very helpful for integration of green lacewings in IPM programs. Copyright © 2016 Elsevier B.V. All rights reserved.

When Smokey says "No": Fire-less methods for growing plants adapted to cultural fire regimes

Treesearch

Daniela Shebitz; Justine E. James

2010-01-01

Two culturally-significant plants (sweetgrass [Anthoxanthum nitens] and beargrass [Xerophyllum tenax]) are used as case studies for investigating methods of restoring plant populations that are adapted to indigenous burning practices without using fire. Reports from tribal members that the plants of interest were declining in traditional gathering areas provided the...

Forest nursery management in Chile

Treesearch

Rene Escobar R.; Manuel Sanchez O.; Guillermo Pereira C.

2002-01-01

The forest economy in Chile is based on products from artificial reforestation efforts on approximately 2 million ha. From these, about 1.5 million ha (75%) are planted with Pinus radiata, 400,000 ha (20%) with species of Eucalyptus, principally E. globulus and E. nitens, and the rest (5%) composed by other...

Pest risk assessment of the importation into the United States of unprocessed logs and chips of eighteen Eucalypt species from Australia.

Treesearch

John T. Kliejunas; Harold H., Jr. Burdsall; Gregg A. DeNitto; Andris Eglitis; Dennis A. Haugen; Michael I. Harverty; Jessie A. Micales; Mark R. Powell

2003-01-01

The unmitigated pest risk potential for the importation of unprocessed logs and chips of 18 species of eucalypts (Eucalyptus amygdalina, E. cloeziana, E. delegatensis, E. diversicolor, E. dunnii, E. globulus, E. grandis, E. nitens, E. obliqua, E. ovata, E. pilularis, E. regnans, E. saligna, E. sieberi, E. viminalis, Corymbia calophylla, C. citriodora, and C. maculata)...

Ticks (Acari: Ixodidae) on wild animals from the Porto-Primavera Hydroelectric power station area, Brazil.

PubMed

Labruna, Marcelo B; de Paula, Cátia D; Lima, Thiago F; Sana, Dênis A

2002-12-01

From June 2000 to June 2001, a total of 741 ticks were collected from 51 free-living wild animals captured at the Porto-Primavera Hydroelectric power station area, located alongside an approximately 180 km course of the Paran river, between the states of S o Paulo and Mato Grosso do Sul, comprising 9 species of 3 genera: Ambly-omma (7 species), Boophilus (1) and Anocentor (1). A total of 421 immature Amblyomma ticks were reared in laboratory until the adult stage, allowing identification of the species. A. cajennense was the most frequent tick species (mostly immature stages) collected on 9 host species: Myrmecophaga tridactyla, Tamandua tetradactyla,Cerdocyon thous, Puma concolor,Tayassu tajacu, Mazama gouazoubira,Hydrochaeris hydrochaeris,Alouatta caraya, Cebus apella. Other tick species were less common, generally restricted to certain host taxa.

An evaluation of the rust fungus Gymnoconia nitensas a potential biological control agent for alien Rubus species in Hawaii

USGS Publications Warehouse

Gardner, D.E.; Hodges, C.S.; Killgore, E.; Anderson, R.C.

1997-01-01

The rust fungus Gymnoconia nitens infects blackberry (Rubus argutus) systemically in regions of the continental United States, producing bright yellow–orange masses of spores on newly developing floricanes during springtime. In tests to determine the suitability of this rust as a biological control agent for R. penetransin Hawaii, a species now thought to be conspecific with R. argutus,rooted cuttings of the Hawaiian plants were grown at North Carolina State University, inoculated, and observed. Other introduced weedy Rubus spp. in Hawaii, including R. ellipticus, R. rosifolius, and R. glaucus,as well as the two endemic species R. hawaiensis and R. macraei,also were inoculated. No species of Rubusare of commercial importance in Hawaii, but the protection of the native species, of which R. macraei is rare, was of utmost concern. The native Hawaiian species did not survive well in North Carolina in this study, however. Later availability of a plant pathogen containment laboratory in Hawaii enabled similar tests to be conducted at that facility. In addition to the above species, R. spectabilis (salmonberry), a species native to the Pacific Northwest with which the Hawaiian Rubus spp. are thought to share a common ancestor, was inoculated in Hawaii. Infection with G. nitens under natural field conditions becomes apparent only when sporulation occurs on floricanes the second year following infection. However, experimental inoculation led to early responses of chlorotic leaf flecking and puckering, leaf and stem contortion, and stem gall formation, indicating the sensitivity of R. penetrans (=R. argutus), R. hawaiensis, and R. macraei to this rust. Apparent systemic infection also resulted in sporulation on one plant of R. macraei. Ability to attack the endemic species suggests that G. nitens would not be suitable for release in Hawaii as a biological control agent, at least on the islands with populations of the native species.

Comparative ecotoxicity of chlorantraniliprole to non-target soil invertebrates.

PubMed

Lavtižar, Vesna; Berggren, Kristina; Trebše, Polonca; Kraak, Michiel H S; Verweij, Rudo A; van Gestel, Cornelis A M

2016-09-01

The insecticide chlorantraniliprole (CAP) is gaining importance in agricultural practice, but data on its possible negative effects on non-target organisms is severely deficient. This study therefore determined CAP toxicity to non-target soil invertebrates playing a crucial role in ecosystem functioning, including springtails (Folsomia candida), isopods (Porcellio scaber), enchytraeids (Enchytraeus crypticus) and oribatid mites (Oppia nitens). In sublethal toxicity tests in Lufa 2.2 soil, chronic exposure to CAP concentrations up to 1000 mg/kgdw did not affect the survival and reproduction of E. crypticus and O. nitens nor the survival, body weight and consumption of P. scaber. In contrast, the survival and reproduction of F. candida was severely affected, with an EC50 for effects on reproduction of 0.14 mg CAP/kgdw. The toxicity of CAP to the reproduction of F. candida was tested in four different soils following OECD guideline 232, and additionally in an avoidance test according to ISO guideline 17512-2. A significantly lower toxicity in soils rich in organic matter was observed, compared to low organic soils. Observations in the avoidance test with F. candida suggest that CAP acted in a prompt way, by affecting collembolan locomotor abilities thus preventing them from escaping contaminated soil. This study shows that CAP may especially pose a risk to non-target soil arthropods closely related to insects, while other soil invertebrates seem rather insensitive. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative toxicity of imidacloprid and thiacloprid to different species of soil invertebrates.

PubMed

de Lima E Silva, Cláudia; Brennan, Nicola; Brouwer, Jitske M; Commandeur, Daniël; Verweij, Rudo A; van Gestel, Cornelis A M

2017-05-01

Neonicotinoid insecticides have come under increasing scrutiny for their impact on non-target organisms, especially pollinators. The current scientific literature is mainly focused on the impact of these insecticides on pollinators and some aquatic insects, leaving a knowledge gap concerning soil invertebrates. This study aimed at filling this gap, by determining the toxicity of imidacloprid and thiacloprid to five species of soil invertebrates: earthworms (Eisenia andrei), enchytraeids (Enchytraeus crypticus), Collembola (Folsomia candida), oribatid mites (Oppia nitens) and isopods (Porcellio scaber). Tests focused on survival and reproduction or growth, after 3-5 weeks exposure in natural LUFA 2.2 standard soil. Imidacloprid was more toxic than thiacloprid for all species tested. F. candida and E. andrei were the most sensitive species, with LC 50 s of 0.20-0.62 and 0.77 mg/kg dry soil for imidacloprid and 2.7-3.9 and 7.1 mg/kg dry soil for thiacloprid. EC 50 s for effects on the reproduction of F. candida and E. andrei were 0.097-0.30 and 0.39 mg/kg dry soil for imidacloprid and 1.7-2.4 and 0.44 mg/kg dry soil for thiacloprid. The least sensitive species were O. nitens and P. scaber. Enchytraeids were a factor of 5-40 less sensitive than the taxonomically related earthworm, depending on the endpoint considered. Although not all the species showed high sensitivity to the neonicotinoids tested, these results raise awareness about the effects these insecticides can have on non-target soil invertebrates.

First molecular evidence of Coxiella burnetii infecting ticks in Cuba.

PubMed

Noda, Angel A; Rodríguez, Islay; Miranda, Jorge; Contreras, Verónica; Mattar, Salim

2016-02-01

Coxiella burnetii is the causative agent of Q fever. In order to explore the occurrence of C. burnetii in ticks, samples were collected from horses, dogs and humans living in a Cuban occidental community. The species most commonly recovered were Amblyomma mixtum (67%), Rhipicephalus sanguineus s.l. (27%) and Dermacentor nitens (6%). Specific IS1111 PCR and amplicon sequencing allowed the identification of C. burnetii DNA in A. mixtum collected from a domestic horse. These findings, for first time in Cuba, indicate the need for an in-depth assessment of the C. burnetii occurrence in hosts and humans at risk of infection. Copyright © 2015 Elsevier GmbH. All rights reserved.

Evolutionary History and Novel Biotic Interactions Determine Plant Responses to Elevated CO2 and Nitrogen Fertilization

PubMed Central

Wooliver, Rachel; Senior, John K.; Schweitzer, Jennifer A.; O'Reilly-Wapstra, Julianne M.; Langley, J. Adam; Chapman, Samantha K.; Bailey, Joseph K.

2014-01-01

A major frontier in global change research is predicting how multiple agents of global change will alter plant productivity, a critical component of the carbon cycle. Recent research has shown that plant responses to climate change are phylogenetically conserved such that species within some lineages are more productive than those within other lineages in changing environments. However, it remains unclear how phylogenetic patterns in plant responses to changing abiotic conditions may be altered by another agent of global change, the introduction of non-native species. Using a system of 28 native Tasmanian Eucalyptus species belonging to two subgenera, Symphyomyrtus and Eucalyptus, we hypothesized that productivity responses to abiotic agents of global change (elevated CO2 and increased soil N) are unique to lineages, but that novel interactions with a non-native species mediate these responses. We tested this hypothesis by examining productivity of 1) native species monocultures and 2) mixtures of native species with an introduced hardwood plantation species, Eucalyptus nitens, to experimentally manipulated soil N and atmospheric CO2. Consistent with past research, we found that N limits productivity overall, especially in elevated CO2 conditions. However, monocultures of species within the Symphyomyrtus subgenus showed the strongest response to N (gained 127% more total biomass) in elevated CO2 conditions, whereas those within the Eucalyptus subgenus did not respond to N. Root:shoot ratio (an indicator of resource use) was on average greater in species pairs containing Symphyomyrtus species, suggesting that functional traits important for resource uptake are phylogenetically conserved and explaining the phylogenetic pattern in plant response to changing environmental conditions. Yet, native species mixtures with E. nitens exhibited responses to CO2 and N that differed from those of monocultures, supporting our hypothesis and highlighting that both plant

Evolutionary history and novel biotic interactions determine plant responses to elevated CO2 and nitrogen fertilization.

PubMed

Wooliver, Rachel; Senior, John K; Schweitzer, Jennifer A; O'Reilly-Wapstra, Julianne M; Langley, J Adam; Chapman, Samantha K; Bailey, Joseph K

2014-01-01

A major frontier in global change research is predicting how multiple agents of global change will alter plant productivity, a critical component of the carbon cycle. Recent research has shown that plant responses to climate change are phylogenetically conserved such that species within some lineages are more productive than those within other lineages in changing environments. However, it remains unclear how phylogenetic patterns in plant responses to changing abiotic conditions may be altered by another agent of global change, the introduction of non-native species. Using a system of 28 native Tasmanian Eucalyptus species belonging to two subgenera, Symphyomyrtus and Eucalyptus, we hypothesized that productivity responses to abiotic agents of global change (elevated CO2 and increased soil N) are unique to lineages, but that novel interactions with a non-native species mediate these responses. We tested this hypothesis by examining productivity of 1) native species monocultures and 2) mixtures of native species with an introduced hardwood plantation species, Eucalyptus nitens, to experimentally manipulated soil N and atmospheric CO2. Consistent with past research, we found that N limits productivity overall, especially in elevated CO2 conditions. However, monocultures of species within the Symphyomyrtus subgenus showed the strongest response to N (gained 127% more total biomass) in elevated CO2 conditions, whereas those within the Eucalyptus subgenus did not respond to N. Root:shoot ratio (an indicator of resource use) was on average greater in species pairs containing Symphyomyrtus species, suggesting that functional traits important for resource uptake are phylogenetically conserved and explaining the phylogenetic pattern in plant response to changing environmental conditions. Yet, native species mixtures with E. nitens exhibited responses to CO2 and N that differed from those of monocultures, supporting our hypothesis and highlighting that both plant

Review of the genus Genaemirum Heinrich (Hymenoptera, Ichneumonidae, Ichneumoninae) with interactive identification keys to species.

PubMed

Rousse, Pascal; Broad, Gavin R; van Noort, Simon

2016-01-01

We describe Genaemirum phagocossorum Rousse, Broad & van Noort, sp. n. , a new ichneumonine parasitoid wasp reared from Eucalyptus nitens logs infested by the cossid moth Coryphodema tristis , which is considered a major pest of forestry and food crops in South Africa. This is the first plausible host association for the genus, and fits with the host association predictions of Heinrich. Two further undescribed species were found in the collections of the Natural History Museum in London and are described as Genaemirum phacochoerus Broad, Rousse & van Noort, sp. n. and Genaemirum fumosum Broad, Rousse & van Noort, sp. n. An identification key to the eight known species and a diagnosis for each species are provided, including photographs of all the primary type specimens. Online Lucid interactive identification keys are available at: http://www.waspweb.org.

Review of the genus Genaemirum Heinrich (Hymenoptera, Ichneumonidae, Ichneumoninae) with interactive identification keys to species

PubMed Central

Rousse, Pascal; Broad, Gavin R.; van Noort, Simon

2016-01-01

Abstract We describe Genaemirum phagocossorum Rousse, Broad & van Noort, sp. n., a new ichneumonine parasitoid wasp reared from Eucalyptus nitens logs infested by the cossid moth Coryphodema tristis, which is considered a major pest of forestry and food crops in South Africa. This is the first plausible host association for the genus, and fits with the host association predictions of Heinrich. Two further undescribed species were found in the collections of the Natural History Museum in London and are described as Genaemirum phacochoerus Broad, Rousse & van Noort, sp. n. and Genaemirum fumosum Broad, Rousse & van Noort, sp. n. An identification key to the eight known species and a diagnosis for each species are provided, including photographs of all the primary type specimens. Online Lucid interactive identification keys are available at: http://www.waspweb.org. PMID:27917066

Specific characteristics of family 45 endoglucanases from Mucorales in the use of textiles and laundry.

PubMed

Shimonaka, Atsushi; Koga, Jinichiro; Baba, Yuko; Nishimura, Tomoko; Murashima, Koichiro; Kubota, Hidetoshi; Kono, Toshiaki

2006-04-01

We examined the characteristics of family 45 endoglucanases (glycoside hydrolases family 45; GH45) from Mucorales belonging to Zygomycota in the use of textiles and laundry. The defibrillation activities on lyocell fabric of family 45 endoglucanases from Mucorales, such as RCE1 and RCE2 from Rhizopus oryzae, MCE1 and MCE2 from Mucor circinelloides, and PCE1 from Phycomyces nitens, were much higher than those of the other family 45 endoglucanases. By contrast, family 45 endoglucanases from Mucorales were less resistant to anionic surfactant and oxidizing agent, main components in detergents, than the other family 45 endoglucanases. RCE1 consists of two distinct modules, a catalytic module and a carbohydrate-binding module family 1 (CBM1), and these common specific characteristics were considered to due to the catalytic module, but not to the CBM1.

Rapid determination of vitellogenin in fish plasma by anion exchange high performance liquid chromatography using postcolumn fluorescence derivatization with o-phthalaldehyde.

PubMed

Wu, Cuiqin; Yuan, Dongxing; Liu, Baomin

2006-12-01

An analytical method involving anion exchange high performance liquid chromatographic determination of vitellogenin (Vtg) in fish plasma after postcolumn fluorescence derivatization with o-phthalaldehyde (OPA) was developed. The retention time of Vtg was about 11 min. The reagent variables for derivatization were optimized. The fluorophore was excited at 335 nm and detected at 435 nm. A calibration curve was established ranging from 0.13 to 11.28 microg. The determination limit of Vtg was found to be as low as 0.13 microg. The spiked recovery was 93.6% and interassay variability was less than 4%. The method developed was used to determine Vtg in fish plasma obtained from red sea bream (Pagrosomus major), black porgy (Sparus macrocephalus) and skew band grunt (Hapalogenys nitens), without complicated sample pretreatment. The results confirmed that the method showed advantages of being simple, rapid, reproducible and sensitive.

Decomposition dynamics of mixed litter in a seasonally flooded forest near the Orinoco river

NASA Astrophysics Data System (ADS)

Bastianoni, Alessia; Chacón, Noemí; Méndez, Carlos L.; Flores, Saúl

2015-04-01

We evaluated the decomposition of a litter mixture in the seasonally flooded forest of a tributary of the Orinoco river. This mixture was prepared using three litter species, based on the litter fall rate observed over a complete hydro-period (2012-2013). The mixture loading ratio was 0.46 of Pouteria orinocoensis (Sapotaceae), 0.38 of Alibertia latifolia (Rubiaceae) and 0.16 of Acosmium nitens (Fabaceae). The initial chemical composition of each single litter species was also determined. Litterbags (20 × 20 cm, 2 mm opening) containing either each single species or the mixture, were deployed on the flooded forest soil and sampled after 30, 240, 270, 300 and 330 days. There were differences in initial total N and P concentrations, with A. nitens (AN) showing the highest nutrient concentrations (%NAN = 1.86 ± 0.19; %PAN = 0.058 ± 0.008) and P. orinocoensis (PO) and A. latifolia (AL) the lowest (%NPO = 0.92 ± 0.06; %NAL = 1.04 ± 0.04; %PPO = 0.029 ± 0.005; %PAL = 0.032 ± 0.001). Litter from AN showed the greatest mass loss (55%) and fastest decomposition rate (k = 0.00185 ± 0.00028) while litter from AL and the mixture showed the smallest mass loss (24% and 27% respectively) and the slowest decomposition rate (kAL = 0.00078 ± 0.00012 and kMIX = 0.00077 ± 0.00006). Decomposition rates were significantly and positively correlated with initial N (r = 0.556, p < 0.05) and P concentrations (r = 0.482, p < 0.05). Nevertheless, there were no significant differences between the expected decomposition rate and the observed decomposition rate of the mixture (additive response). To test the nature of the additivity, an enhancement factor (f) on decomposition rates for each single species was calculated. The species with the highest and smallest value of f were AN and AL, respectively. The fact that two out of the three species had values significantly different from 1, suggests that the additivity detected in our mixture was a consequence of the counterbalancing of

Maternal inheritance of the chloroplast genome in Eucalyptus globulus and interspecific hybrids.

PubMed

Mckinnon, A E; Vaillancourt, R E; Tilyard, P A; Potts, B M

2001-10-01

The utility of chloroplast DNA (cpDNA) in Eucalyptus, either as a molecular marker for genetic studies or as a potential vehicle for genetic manipulation, is based on knowledge of its mode of inheritance. Chloroplast inheritance in angiosperms can vary among and within species, and anomalous inheritance has been reported in some interspecific-hybrid combinations. In Eucalyptus, abnormalities of pollen-tube growth occur in a number of interspecific-hybrid combinations, and this might increase the likelihood of anomalous chloroplast transmission. We used a rapid PCR technique to determine chloroplast heritability in 425 progeny of Eucalyptus, comprising 194 progeny of the premier pulpwood species E. globulus and 231 interspecific hybrids between E. globulus and E. nitens (F1, F2, and backcrosses). At this sampling intensity, no pollen-mediated transmission of cpDNA was found in any of the 40 families tested. The results are discussed with reference to chloroplast engineering and the use of cpDNA as a seed-specific marker in phylogeographic studies of Eucalyptus.

Cytogenetic analysis of five Hypostomus species (Siluriformes, Loricariidae)

PubMed Central

Martinez, Emanuel Ricardo Monteiro; Zawadzki, Claudio Henrique; Foresti, Fausto; Oliveira, Claudio

2011-01-01

In this work, we analyzed the karyotypes of five Hypostomus species. Hypostomus cf. heraldoi, from the Mogi-Guaçu River, had 2n = 72 chromosomes, with a nucleolar organizer region (NOR) in one chromosomal pair. Hypostomus regani, from the Mogi-Guaçu River had 2n = 72 chromosomes with NORs in two chromosomal pairs. Hypostomus sp., from the Mogi-Guaçu River basin, had 2n = 68 chromosomes, with NORs in two chromosomal pairs. Hypostomus aff. agna, from Cavalo Stream, had 2n = 74 chromosomes with NORs in two chromosomal pairs. Hypostomus cf. topavae, from Carrapato Stream, had 2n = 80 chromosomes, with NORs in two chromosomal pairs. Hypostomus species showed marked diversity in the karyotypic formula, which suggested the occurrence of several Robertsonian rearrangements and pericentric inversions during the evolutionary history of this genus. This hypothesis was supported by the occurrence of a large number of uniarmed chromosomes and multiple NORs in a terminal position in most species and may be a derived condition in the Loricariidae. PMID:22215958

The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Bolivia.

PubMed

Mastropaolo, Mariano; Beltrán-Saavedra, L Fabián; Guglielmone, Alberto A

2014-03-01

The tick species reported in Bolivia are reviewed here as (1) endemic or established: Ornithodoros echimys, O. guaporensis, O. hasei, O. kohlsi, O. mimon, O. peropteryx, O. rostratus, Otobius megnini, Amblyomma auricularium, A. cajennense, A. calcaratum, A. coelebs, A. dubitatum, A. humerale, A. incisum, A. longirostre, A. naponense, A. nodosum, A. oblongoguttatum, A. ovale, A. parvitarsum, A. parvum, A. pecarium, A. pseudoconcolor, A. rotundatum, A. scalpturatum, A. tigrinum, A. triste, Dermacentor nitens, Haemaphysalis juxtakochi, H. leporispalustris, I. boliviensis, I. cooleyi, I. luciae, Rhipicephalus microplus, R. sanguineus, and (2) erroneously reported: Ornithodoros puertoricensis, O. talaje, O. turicata, Amblyomma americanum, A. maculatum, A. multipunctum, Ixodes ricinus, I. scapularis, Rhipicephalus annulatus. Many of these records are lacking locality and/or host, and some of them need new findings for confirmation. Some of the species recorded may represent a threat for human and animal health, therefore would be of great value to make a countrywide survey of ticks in order to update the information presented in this work. Copyright © 2013 Elsevier GmbH. All rights reserved.

Glycine decarboxylase is confined to the bundle-sheath cells of leaves of C3-C 4 intermediate species.

PubMed

Hylton, C M; Rawsthorne, S; Smith, A M; Jones, D A; Woolhouse, H W

1988-10-01

Immunogold labelling has been used to determine the cellular distribution of glycine decarboxylase in leaves of C3, C3-C4 intermediate and C4 species in the genera Moricandia, Panicum, Flaveria and Mollugo. In the C3 species Moricandia foleyi and Panicum laxum, glycine decarboxylase was present in the mitochondria of both mesophyll and bundle-sheath cells. However, in all the C3-C4 intermediate (M. arvensis var. garamatum, M. nitens, M. sinaica, M. spinosa, M. suffruticosa, P. milioides, Flaveria floridana, F. linearis, Mollugo verticillata) and C4 (P. prionitis, F. trinervia) species studied glycine decarboxylase was present in the mitochondria of only the bundle-sheath cells. The bundle-sheath cells of all the C3-C4 intermediate species have on their centripetal faces numerous mitochondria which are larger in profile area than those in mesophyll cells and are in close association with chloroplasts and peroxisomes. Confinement of glycine decarboxylase to the bundle-sheath cells is likely to improve the potential for recapture of photorespired CO2 via the Calvin cycle and could account for the low rate of photorespiration in all C3-C4 intermediate species.

Genomic patterns of species diversity and divergence in Eucalyptus.

PubMed

Hudson, Corey J; Freeman, Jules S; Myburg, Alexander A; Potts, Brad M; Vaillancourt, René E

2015-06-01

We examined genome-wide patterns of DNA sequence diversity and divergence among six species of the important tree genus Eucalyptus and investigated their relationship with genomic architecture. Using c. 90 range-wide individuals of each Eucalyptus species (E. grandis, E. urophylla, E. globulus, E. nitens, E. dunnii and E. camaldulensis), genetic diversity and divergence were estimated from 2840 polymorphic diversity arrays technology markers covering the 11 chromosomes. Species differentiating markers (SDMs) identified in each of 15 pairwise species comparisons, along with species diversity (HHW ) and divergence (FST ), were projected onto the E. grandis reference genome. Across all species comparisons, SDMs totalled 1.1-5.3% of markers and were widely distributed throughout the genome. Marker divergence (FST and SDMs) and diversity differed among and within chromosomes. Patterns of diversity and divergence were broadly conserved across species and significantly associated with genomic features, including the proximity of markers to genes, the relative number of clusters of tandem duplications, and gene density within or among chromosomes. These results suggest that genomic architecture influences patterns of species diversity and divergence in the genus. This influence is evident across the six species, encompassing diverse phylogenetic lineages, geography and ecology. © 2015 University of Tasmania New Phytologist © 2015 New Phytologist Trust.

Description of the immature stages and redescription of the female of Ixodes schulzei Aragão & Fonseca, 1951 (Acari: Ixodidae), an endemic tick species of Brazil.

PubMed

Barros-Battesti, Darci M; Onofrio, Valeria C; Faccini, João L H; Labruna, Marcelo B; Arruda-Santos, Ana D; Giacomin, Flávia G

2007-11-01

Ixodes schulzei Aragão & Fonseca, 1951 is a tick endemic to Brazil, where nine species of Ixodes Latreille, 1796 are currently known to occur. Larvae, nymphs and females of I. schulzei were obtained from a laboratory colony originating from an engorged female collected on a free-living water rat Nectomys squamipes from the Santa Branca municipality, São Paulo State. Only female ticks were obtained from engorged nymphs. Unfed immature and female adult specimens were measured and the descriptions were based on optical and scanning electron microscopy, as were drawings of some features of the larva. Both immature stages present the very long palpi and basis capituli, and the female has large, contiguous porose areas. However, the basis capituli is triangular, with a slight central elevation in the larva and nymph, whereas in the female this area is depressed. The I. schulzei types deposited at the FIOCRUZ (Instituto Oswaldo Cruz) were also examined, as was other material from collections, such as the IBSP (Coleção Acarológica do Instituto Butantan), CNC-FMVZ/USP (Coleção Nacional de Carrapatos da Faculdade de Medicina Veterinária e Zootecnia da USP) and USNTC (United States National Tick Collection). In addition, the relationship between I. schulzei and other immature neotropical species of Ixodes is discussed.

Effects of Temephos, Permethrin, and Eucalyptus nitens Essential Oil on Survival and Swimming Behavior of Aedes aegypti and Anopheles pseudopunctipennis (Diptera: Culicidae) Larvae.

PubMed

Alvarez Costa, Agustín; Gonzalez, Paula V; Harburguer, Laura V; Masuh, Héctor M

2018-06-04

An essential strategy to deal with mosquito-borne diseases is the control of larvae in their development sites. The mosquitoes Anopheles pseudopunctipennis (Theobald) (Diptera: Culicidae), a malaria vector, and Aedes aegypti (L.) (Diptera: Culicidae), vector of dengue, Zika, yellow fever, and chikungunya viruses, breed in very different habitats. Insecticide treatments of mosquito larvae focus mainly on their lethal effects. However, insecticide degradation or the poor dosage of larvicides will invariably lead to the sublethal exposure of a target (and nontarget) species, the nonlethal effects of these compounds may have important effects on vital insect activities, and therefore their evaluation is necessary. In this study, we assessed the survival and swimming behavior of larvae of Ae. aegypti and An. pseudopunctipennis exposed to increasing concentrations of three larvicides. We found that Ae. aegypti, was more sensitive to the larvicides than An. pseudopunctipennis, we also observed an overall decrease in the movement of those larvae of both species, which survive the treatments. This decrease might have ecological relevance in their natural habitats, increasing the chance to be predated and decreasing their ability to obtain food. Finally, this information will be valuable to assist authorities to make decisions in the implementation of further control programs.

Commercial tree species discrimination using airborne AISA Eagle hyperspectral imagery and partial least squares discriminant analysis (PLS-DA) in KwaZulu-Natal, South Africa

NASA Astrophysics Data System (ADS)

Peerbhay, Kabir Yunus; Mutanga, Onisimo; Ismail, Riyad

2013-05-01

Discriminating commercial tree species using hyperspectral remote sensing techniques is critical in monitoring the spatial distributions and compositions of commercial forests. However, issues related to data dimensionality and multicollinearity limit the successful application of the technology. The aim of this study was to examine the utility of the partial least squares discriminant analysis (PLS-DA) technique in accurately classifying six exotic commercial forest species (Eucalyptus grandis, Eucalyptus nitens, Eucalyptus smithii, Pinus patula, Pinus elliotii and Acacia mearnsii) using airborne AISA Eagle hyperspectral imagery (393-900 nm). Additionally, the variable importance in the projection (VIP) method was used to identify subsets of bands that could successfully discriminate the forest species. Results indicated that the PLS-DA model that used all the AISA Eagle bands (n = 230) produced an overall accuracy of 80.61% and a kappa value of 0.77, with user's and producer's accuracies ranging from 50% to 100%. In comparison, incorporating the optimal subset of VIP selected wavebands (n = 78) in the PLS-DA model resulted in an improved overall accuracy of 88.78% and a kappa value of 0.87, with user's and producer's accuracies ranging from 70% to 100%. Bands located predominantly within the visible region of the electromagnetic spectrum (393-723 nm) showed the most capability in terms of discriminating between the six commercial forest species. Overall, the research has demonstrated the potential of using PLS-DA for reducing the dimensionality of hyperspectral datasets as well as determining the optimal subset of bands to produce the highest classification accuracies.

Ecophysiological Response on Dehydration and Temperature in Terrestrial Klebsormidium (Streptophyta) Isolated from Biological Soil Crusts in Central European Grasslands and Forests.

PubMed

Donner, Antje; Glaser, Karin; Borchhardt, Nadine; Karsten, Ulf

2017-05-01

The green algal genus Klebsormidium (Klebsormidiophyceae, Streptophyta) is a typical member of biological soil crusts (BSCs) worldwide. Ecophysiological studies focused so far on individual strains and thus gave only limited insight on the plasticity of this genus. In the present study, 21 Klebsormidium strains (K. dissectum, K. flaccidum, K. nitens, K. subtile) from temperate BSCs in Central European grassland and forest sites were investigated. Photosynthetic performance under desiccation and temperature stress was measured under identical controlled conditions. Photosynthesis decreased during desiccation within 335-505 min. After controlled rehydration, most isolates recovered, but with large variances between single strains and species. However, all K. dissectum strains had high recovery rates (>69%). All 21 Klebsormidium isolates exhibited the capability to grow under a wide temperature range. Except one strain, all others grew at 8.5 °C and four strains were even able to grow at 6.2 °C. Twenty out of 21 Klebsormidium isolates revealed an optimum growth temperature >17 °C, indicating psychrotrophic features. Growth rates at optimal temperatures varied between strains from 0.26 to 0.77 μ day -1 . Integrating phylogeny and ecophysiological traits, we found no phylogenetic signal in the traits investigated. However, multivariate statistical analysis indicated an influence of the recovery rate and growth rate. The results demonstrate a high infraspecific and interspecific physiological plasticity, and thus wide ecophysiological ability to cope with strong environmental gradients. This might be the reason why members of the genus Klebsormidium successfully colonize terrestrial habitats worldwide.

Ticks (Acari: Ixodidae) of the state of Amazonas, Brazil.

PubMed

Gianizella, Sergio L; Martins, Thiago F; Onofrio, Valeria C; Aguiar, Nair O; Gravena, Waleska; do Nascimento, Carlos A R; Neto, Laérzio C; Faria, Diogo L; Lima, Natália A S; Solorio, Monica R; Maranhão, Louise; Lima, Ivan J; Cobra, Iury V D; Santos, Tamily; Lopes, Gerson P; Ramalho, Emiliano E; Luz, Hermes R; Labruna, Marcelo B

2018-02-01

The tick fauna of Brazil is currently composed by 72 species. The state of Amazonas is the largest of Brazil, with an area of ≈ 19% of the Brazilian land. Besides its vast geographic area, only 19 tick species have been reported for Amazonas. Herein, lots containing ticks from the state of Amazonas were examined in three major tick collections from Brazil. A total of 5933 tick specimens were examined and recorded, comprising 2693 males, 1247 females, 1509 nymphs, and 484 larvae. These ticks were identified into the following 22 species: Amblyomma cajennense sensu lato, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma dissimile, Amblyomma dubitatum, Amblyomma geayi, Amblyomma goeldii, Amblyomma humerale, Amblyomma latepunctatun, Amblyomma longirostre, Amblyomma naponense, Amblyomma oblongoguttatum, Amblyomma ovale, Amblyomma rotundatum, Amblyomma scalpturatum, Amblyomma varium, Dermacentor nitens, Haemaphysalis juxtakochi, Ixodes cf. Ixodes fuscipes, Ixodes luciae, Rhipicephalus microplus, Rhipicephalus sanguineus sensu lato. Ticks were collected from 17 (27.4%) out of the 62 municipalities that currently compose the state of Amazonas. The following four species are reported for the first time in the state of Amazonas: A. coelebs, A. dubitatum, H. juxtakochi, and Ixodes cf. I. fuscipes. The only tick species previously reported for Amazonas and not found in the present study is Amblyomma parvum. This study provides a great expansion of geographical and host records of ticks for the state of Amazonas, which is now considered to have a tick fauna composed by 23 species. It is noteworthy that we report 1391 Amblyomma nymphs that were identified to 13 different species.

The geographic distribution of Argas (Persicargas) miniatus and Argas (Persicargas) persicus (Acari: Argasidae) in America, with morphological and molecular diagnoses from Brazil, Chile and Cuba.

PubMed

Muñoz-Leal, Sebastián; Venzal, José M; Nava, Santiago; Reyes, Mercedes; Martins, Thiago F; Leite, Romário C; Vilela, Vinicius L R; Benatti, Hector R; Ríos-Rosas, Daniela; Barros-Battesti, Darci M; González-Acuña, Daniel; Labruna, Marcelo B

2018-01-01

High similarity of morphological traits has historically overshadowed the identities and distributions of poultry-associated soft ticks Argas (Persicargas) miniatus and Argas (Persicargas) persicus in America. In order to model the occurrence of both parasites in the continent, in the current study we performed morphological and molecular analyses to identify ticks collected in hen houses from Brazil and northern Chile. Combining these results with literature data, and the examination of Argas allotments deposited in the tick collections "Coleção Nacional de Carrapatos Danilo Gonçalves Saraiva" (Brazil), the "Coleção Acarológica do Instituto Butantan São Paulo" (Brazil), and the "Colección Zoológica de la Academia de Ciencia de Cuba" (Cuba), we present a critical list with the localities where A. (P.) miniatus and A. (P.) persicus have been reported in the American continent. Our results confirmed the presence of A. (P.) miniatus in Brazil and Cuba, and A. (P.) persicus in Chile, which in particular, constitutes the first molecularly confirmed report of the later species for South America. Although A. (P.) miniatus and A. (P.) persicus have been documented in 21 American countries, the identity of some reports must still be considered as uncertain until detailed morphological and/or molecular studies are performed. When contrasted to a Köppen-Geiger climate classification, A. (P.) miniatus predominantly occurs in equatorial and A. (P.) persicus in arid climates. However, until undetermined reports of both species are correctly identified, any conclusion on their geo-climatological occurrence throughout the American continent would be rather speculative. Copyright © 2017 Elsevier GmbH. All rights reserved.

Spotted Fever: Epidemiology and Vector-Rickettsia-Host Relationship in Rio de Janeiro State

PubMed Central

Montenegro, Diego C.; Bitencourth, Karla; de Oliveira, Stefan V.; Borsoi, Ana P.; Cardoso, Karen M.; Sousa, Maria S. B.; Giordano-Dias, Cristina; Amorim, Marinete; Serra-Freire, Nicolau M.; Gazêta, Gilberto S.; Brazil, Reginaldo P.

2017-01-01

The eco-epidemiological scenario of spotted fever (SF), a tick-borne disease that affects humans and other animals in several countries around the world, was analyzed in Rio de Janeiro (RJ) State, Brazil. During the last 34 years, 990 SF cases were reported in RJ (the Brazilian state with the highest population density), including 116 cases confirmed by serology (RIFI) or PCR, among 42.39% of the municipalities with reported cases of SF. The epidemiologic dynamics of SF in RJ State are very heterogeneous in time and space, with outbreaks, high mortality rates and periods of epidemiological silence (no SF cases reported). Furthermore, it exhibited a changing epidemiological profile from being rural to becoming an urban disease. This study identified arthropods infected with Rickettsia felis, R. bellii and R. rickettsii, and found that the abundance of ectoparasites was associated with specific hosts. The R. rickettsii-vector-host relationship was most evident in species-specific parasitism. This suggests that the association between dogs, cattle, horses, capybaras and their main ectoparasites, Rhipicephalus sanguineus and Ctenocephalides felis, Rhipicephalus microplus, Dermacentor nitens, and Amblyomma dubitatum, respectively, has a key role in the dynamics of R. rickettsii transmission in enzootic cycles and the maintenance of carrier ectoparasites, thus facilitating the existence of endemic areas with the ability to produce epidemic outbreaks of SF in RJ. This study found confirmed human infections for only the R. rickettsii carrier Amblyomma sculptum, which reinforces the importance of this species as a vector of the pathogen in Brazil. This study can be adapted to different eco-epidemiological scenarios of spotted fever throughout the Americas. PMID:28424664

The potentiation of zinc toxicity by soil moisture in a boreal forest ecosystem.

PubMed

Owojori, Olugbenga J; Siciliano, Steven D

2015-03-01

Northern boreal forests often experience forest dieback as a result of metal ore mining and smelting. The common solution is to lime the soil, which increases pH, reducing metal toxicity and encouraging recovery. In certain situations, however, such as in Flin Flon, Manitoba, Canada, liming has yielded only moderate benefits, with some locations responding well to liming and other locations not at all. In an effort to increase the effectiveness of the ecorestoration strategy, the authors investigated if these differences in liming responsiveness were linked to differences in toxicity. Toxicity of metal-impacted Flin Flon soils on the oribatid mite Oppia nitens and the collembolan Folsomia candida was assessed, with a view toward identifying the metal of concern in the area. The effects of moisture content on metal sorption, uptake, and toxicity to the invertebrates were also investigated. Toxicity tests with the invertebrates were conducted using either Flin Flon soils or artificial soils with moisture content adjusted to 30%, 45%, 60%, or 75% of the maximum water-holding capacity of the soil samples. The Relative to Cd Toxicity Model identified Zn as the metal of concern in the area, and this was confirmed using validation tests with field contaminated soils. Furthermore, increasing the moisture content in soils increased the amount of mobile Zn available for uptake with the ion exchange resin. Survival and reproduction of both invertebrates were reduced under Zn exposure as moisture level increased. Thus, moisture-collecting landforms, which are often also associated with high Zn concentrations at Flin Flon, have, as a result, higher Zn toxicity to the soil ecosystem because of increases in soil moisture. © 2014 SETAC.

[Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico].

PubMed

López-Martínez, Juana; Acevedo-Cervantes, Alejandro; Herrera-Valdivia, Eloisa; Rodríguez-Romero, Jesús; Palacios-Salgado, Deivis S

2012-03-01

The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling difficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California's geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

Detection of rickettsiae in fleas and ticks from areas of Costa Rica with history of spotted fever group rickettsioses.

PubMed

Troyo, Adriana; Moreira-Soto, Rolando D; Calderon-Arguedas, Ólger; Mata-Somarribas, Carlos; Ortiz-Tello, Jusara; Barbieri, Amália R M; Avendaño, Adrián; Vargas-Castro, Luis E; Labruna, Marcelo B; Hun, Laya; Taylor, Lizeth

2016-10-01

Outbreaks of spotted fevers have been reported in Costa Rica since the 1950s, although vectors responsible for transmission to humans have not been directly identified. In this study, species of Rickettsia were detected in ectoparasites from Costa Rica, mostly from five study sites where cases of spotted fevers have been reported. Ticks and fleas were collected using drag cloths or directly from domestic and wild animals and pooled according to species, host, and location. Pools were analyzed initially by PCR to detect a fragment of Rickettsia spp. specific gltA gene, and those positive were confirmed by detection of htrA and/or ompA gene fragments. Partial sequences of the gltA gene were obtained, as well as at least one ompA and/or ompB partial sequence of each species. Rickettsia spp. were confirmed in 119 of 497 (23.9%) pools of ticks and fleas analyzed. Rickettsia rickettsii was identified in one nymph of Amblyomma mixtum and one nymph of Amblyomma varium. Other rickettsiae present were 'Candidatus Rickettsia amblyommii' in A. mixtum, Amblyomma ovale, Dermacentor nitens, and Rhipicephalus sanguineus s. l.; Rickettsia bellii in Amblyomma sabanerae; Rickettsia felis in Ctenocephalides felis; and Rickettsia sp. similar to 'Candidatus R. asemboensis' in C. felis, Pulex simulans, A. ovale, and Rhipicephalus microplus. Results show the presence of rickettsiae in vectors that may be responsible for transmission to humans in Costa Rica, and evidence suggests exposure to rickettsial organisms in the human environment may be common. This is the first study to report R. rickettsii in A. varium and in A. mixtum in Costa Rica. Copyright © 2016 Elsevier GmbH. All rights reserved.

Molecular Detection and Identification of Rickettsia Species in Ticks (Acari: Ixodidae) Collected From Belize, Central America.

PubMed

Polsomboon, Suppaluck; Hoel, David F; Murphy, Jittawadee R; Linton, Yvonne-Marie; Motoki, Maysa; Robbins, Richard G; Bautista, Kim; Bricen O, Ireneo; Achee, Nicole L; Grieco, John P; Ching, Wei-Mei; Chao, Chien-Chung

2017-11-07

Little is known about tick-borne rickettsial pathogens in Belize, Central America. We tested ixodid ticks for the presence of Rickettsia species in three of the six northern and western Belizean districts. Ticks were collected from domestic animals and tick drags over vegetation in 23 different villages in November 2014, February 2015, and May 2015. A total of 2,506 collected ticks were identified to the following species: Dermacentor nitens Neumann (46.69%), Rhipicephalus sanguineus (Latreille) (19.55%), Rhipicephalus microplus (Canestrini) (19.47%), Amblyomma cajennense complex (9.74%), Amblyomma maculatum Koch (3.47%), Amblyomma ovale Koch (0.68%), Ixodes nr affinis (0.16%), Amblyomma nr maculatum (0.12%), and Amblyomma nr oblongoguttatum (0.12%). Ticks were pooled according to species, life stage (larva, nymph, or adult), and location (n = 509) for DNA extraction and screened for genus Rickettsia by quantitative real-time polymerase chain reaction (qPCR). All 42 positive pools were found to be positive for spotted fever group (SFG) Rickettsia in pools of A. cajennense complex (n = 33), A. maculatum (n = 4), A. nr maculatum (n = 1), A. ovale (n = 1), R. sanguineus (n = 1), and I. nr affinis (n = 2). Rickettsia amblyommatis was identified from A. cajennense complex and A. nr maculatum. Rickettsia parkeri was found in A. maculatum, and Rickettsia sp. endosymbiont was detected in I. nr affinis. The presence of infected ticks suggests a risk of tick-borne rickettsioses to humans and animals in Belize. This knowledge can contribute to an effective tick management and disease control program benefiting residents and travelers. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Plant, Microbiome, and Biogeochemistry: Quantifying moss-associated N fixation in Alaska

NASA Astrophysics Data System (ADS)

Stuart, J.; Mack, M. C.; Holland Moritz, H.; Fierer, N.; McDaniels, S.; Lewis, L.

2017-12-01

The future carbon (C) sequestration potential of the Arctic and boreal zones, currently the largest terrestrial C sink globally, is linked to nitrogen (N) cycling and N availability vis-a-vis C accumulation and plant species composition. Pristine environments in Alaska have low anthropogenic N deposition (<1 kg N ha-1 yr-1), and the main source of new N to these ecosystems is through previously overlooked N-fixation from microbial communities on mosses. Despite the importance of moss associated N-fixation, the relationship between moss species, microbial communities, and fixation rates remains ambiguous. In the summer of 2016, the fixation rates of 20 moss species from sites around both Fairbanks and Toolik Lake were quantified using 15N2 incubations. Subsequently, the microbial community and moss genome of the samples were also analyzed by collaborators. The most striking result is that all sampled moss genera fixed N, including well-studied feather mosses such as Hylocomium splendens and Pleurozium schreberi as well as less common but ecologically relevant mosses such as Aulacomnium spp., Dicranum spp., Ptilium crista-castrensis, and Tomentypnum nitens. Across all samples, preliminary fixation rates ranged from 0.004-19.994 µg N g-1 moss d-1. Depending upon percent cover, moss-associated N fixation is the largest input of new N to the ecosystem. Given this, linking variation in N-fixation rates to microbial and moss community structures can be helpful in predicting future trends of C and N cycling in northern latitudes. Vegetation changes, alterations in downstream biogeochemical N processes, and anthropogenic N deposition could all interact with or alter moss associated N-fixation, thereby changing ecosystem N inputs. Further elucidation of the species level signal in N-fixation rates and microbial community will augment our knowledge of N cycling in northern latitudes, both current and future.

Petroleum Hydrocarbon Mixture Toxicity and a Trait Based Approach to Soil Invertebrate Species for Site Specific Risk Assessments.

PubMed

Gainer, Amy; Cousins, Mark; Hogan, Natacha; Siciliano, Steven D

2018-05-05

Although petroleum hydrocarbons (PHCs) released to the environment typically occur as mixtures, PHC remediation guidelines often reflect individual substance toxicity. It is well documented that groups of aliphatic PHCs act via the same mechanism of action, nonpolar narcosis and, theoretically, concentration addition mixture toxicity principles apply. To assess this theory, ten standardized acute and chronic soil invertebrate toxicity tests on a range of organisms (Eisenia fetida, Lumbricus terrestris, Enchytraeus crypticus, Folsomia candida, Oppia nitens and Hypoaspis aculeifer) were conducted with a refined PHC binary mixture. Reference models for concentration addition and independent action were applied to the mixture toxicity data with consideration of synergism, antagonism and dose level toxicity. Both concentration addition and independent action, without further interactions, provided the best fit with observed response to the mixture. Individual fraction effective concentration values were predicted from optimized, fitted reference models. Concentration addition provided a better estimate than independent action of individual fraction effective concentrations based on comparison with available literature and species trends observed in toxic responses to the mixture. Interspecies differences in standardized laboratory soil invertebrate species responses to PHC contaminated soil was reflected in unique traits. Diets that included soil, large body size, permeable cuticle, low lipid content, lack of ability to molt and no maternal transfer were traits linked to a sensitive survival response to PHC contaminated soil in laboratory tests. Traits linked to sensitive reproduction response in organisms tested were long life spans with small clutch sizes. By deriving single fraction toxicity endpoints considerate of mixtures, we reduce resources and time required in conducting site specific risk assessments for the protection of soil organism's exposure pathway. This

Late Holocene Permafrost Aggradation in the Western Kenai Lowlands, Alaska: Implications for Climate Reconstruction and Carbon Cycling.

NASA Astrophysics Data System (ADS)

Hoefke, K.; Jones, M.; Jones, B. M.

2017-12-01

Rapid permafrost thaw is occurring throughout the permafrost zone, particularly at the southern margins, where mean annual air temperatures are above 0°C. As the Kenai lowlands experience ecosystem shifts due to human disturbance and climate change, understanding permafrost history is of particular interest given the direct impacts on hydrology, vegetation, and carbon cycling. Across the northern high latitudes, permafrost peatlands within the sporadic and isolated permafrost zone store 95 Pg of C and permafrost formation processes (i.e., syngenetic versus epigenetic) are thought to influence the degree of carbon loss following thaw. This study uses plant macrofossils and radiocarbon dating to determine the timing of permafrost aggradation of a recently-thawed (since 1950 CE) peatland located directly adjacent to a 5-meter thick permafrost plateau landform in the Kenai Peninsula lowlands in south-central Alaska. The coring site was selected using remote sensing imagery to identify areas where permafrost plateaus have been thawing since 1950 CE. Preliminary results show dominance of brown moss (Paludella squarrosa, Drepanocladus spp., Tomenthypnum nitens) and sedge (Carex spp.) from peat inception 11,700 cal yr BP to 3,000 cal yr BP indicative of a permafrost-free rich fen. A transition to silvic peat (Betula nana, Vaccinium oxycoccus, Ledum groenlandicum, ericaceous shrub macrofossils) 3,000 cal yr BP (indicates that permafrost aggradation coincided with neoglacial cooling. Since permafrost aggraded 9000 years after peat accumulation began and permafrost deepened to 5 m into unfrozen peat, this suggests mean annual air temperatures decreased significantly below 0ºC for several millennia in the late Holocene on the Kenai lowlands. This study will also examine impacts of permafrost aggradation and degradation on rates of carbon accumulation and loss.

A robust multi-kernel change detection framework for detecting leaf beetle defoliation using Landsat 7 ETM+ data

NASA Astrophysics Data System (ADS)

Anees, Asim; Aryal, Jagannath; O'Reilly, Małgorzata M.; Gale, Timothy J.; Wardlaw, Tim

2016-12-01

A robust non-parametric framework, based on multiple Radial Basic Function (RBF) kernels, is proposed in this study, for detecting land/forest cover changes using Landsat 7 ETM+ images. One of the widely used frameworks is to find change vectors (difference image) and use a supervised classifier to differentiate between change and no-change. The Bayesian Classifiers e.g. Maximum Likelihood Classifier (MLC), Naive Bayes (NB), are widely used probabilistic classifiers which assume parametric models, e.g. Gaussian function, for the class conditional distributions. However, their performance can be limited if the data set deviates from the assumed model. The proposed framework exploits the useful properties of Least Squares Probabilistic Classifier (LSPC) formulation i.e. non-parametric and probabilistic nature, to model class posterior probabilities of the difference image using a linear combination of a large number of Gaussian kernels. To this end, a simple technique, based on 10-fold cross-validation is also proposed for tuning model parameters automatically instead of selecting a (possibly) suboptimal combination from pre-specified lists of values. The proposed framework has been tested and compared with Support Vector Machine (SVM) and NB for detection of defoliation, caused by leaf beetles (Paropsisterna spp.) in Eucalyptus nitens and Eucalyptus globulus plantations of two test areas, in Tasmania, Australia, using raw bands and band combination indices of Landsat 7 ETM+. It was observed that due to multi-kernel non-parametric formulation and probabilistic nature, the LSPC outperforms parametric NB with Gaussian assumption in change detection framework, with Overall Accuracy (OA) ranging from 93.6% (κ = 0.87) to 97.4% (κ = 0.94) against 85.3% (κ = 0.69) to 93.4% (κ = 0.85), and is more robust to changing data distributions. Its performance was comparable to SVM, with added advantages of being probabilistic and capable of handling multi-class problems

Lanthanum toxicity to five different species of soil invertebrates in relation to availability in soil.

PubMed

Li, Jinxia; Verweij, Rudo A; van Gestel, Cornelis A M

2018-02-01

This study determined the toxicity of lanthanum, one of the most commonly used rare earth elements (REEs), to five representative soil invertebrates after 3-4 weeks exposure. Toxicity was related to total, 0.01 M CaCl 2 -extractable and porewater concentrations in the standard LUFA 2.2 soil, and for earthworms also to body concentrations. La sorption to LUFA 2.2 soil, estimated by relating total soil concentrations to CaCl 2 -extractable or porewater concentrations seemed to reach saturation at >1000 mg La/kg dry soil. Isopod (Porcellio scaber) growth was the most sensitive endpoint, followed by earthworm (Eisenia andrei), enchytraeid (Enchytraeus crypticus), springtail (Folsomia candida) and oribatid mite (Oppia nitens) reproduction, with EC 50 s of 312 (95% confidence interval: 5.6-619), 529 (295-762), 1010 ((>377 < 3133), 1220 (1180-1250) and 1500 (1250-1750) mg La/kg dry soil, respectively. EC 50 s related to CaCl 2 -extractable concentrations ranged between 1.3 (0.046-2.6) and 15.6 (5.6-25.7) mg La/kg dry soil, while porewater-based EC 50 s were 3.5 (-) and 10.2 (-) mg/L for the springtails and mites, respectively. La uptake in the earthworms linearly increased with increasing exposure concentration with bioaccumulation factors ranging between 0.04 and 0.53 (average ± SE: 0.24 ± 0.032). EC 50 for effects on earthworm reproduction related to internal concentrations was 184 (61-301) mg La/kg dry body weight. A risk assessment based on the available toxicity for soil invertebrates, bacteria and plants resulted in an HC 5 of approx. 50 mg La/kg dry soil, suggesting that La may affect soil ecosystems at concentrations slightly above natural background levels (6.6-50 mg La/kg dry soil) in non-polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validation of models to estimate the fumigant and larvicidal activity of Eucalyptus essential oils against Aedes aegypti (Diptera: Culicidae).

PubMed

Lucia, Alejandro; Juan, Laura W; Zerba, Eduardo N; Harrand, Leonel; Marcó, Martín; Masuh, Hector M

2012-05-01

The aim of this work is to validate the pre-existing models that relate the larvicidal and adulticidal activities of the Eucalyptus essential oils on Aedes aegypti. Previous works at our laboratory described that the larvicidal activity of Eucalyptus essential oils can be estimated from the relative concentration of two main components (p-cymene and 1,8-cineole) and that the adulticidal effectiveness can be explained, to a great extent, by the presence of large amounts of the component 1,8-cineole in it. In general, the results show that the higher adulticidal effect of essential oils the lower their larvicidal activity. Fresh leaves was harvested and distilled. Once the essential oil was obtained, the chemical composition was analysed, evaluating the biological activity of 15 species of the genus Eucalyptus (Eucalyptus badjensis Beuzev and Welch, Eucalyptus badjensis × nitens, Eucalyptus benthamii var Benthamii Maiden and Cambage, Eucalyptus benthamii var dorrigoensis Maiden and Cambage, Eucalyptus botryoides Smith, Eucalyptus dalrympleana Maiden, Eucalyptus fastigata Deane and Maiden, Eucalyptus nobilis L.A.S. Johnson and K.D.Hill, Eucalyptus polybractea R. Baker, Eucalyptus radiata ssp radiata Sieber ex Spreng, Eucalyptus resinifera Smith, Eucalyptus robertsonii Blakely, Eucalyptus robusta Smith, Eucalyptus rubida Deane and Maiden, Eucalyptus smithii R. Baker). Essential oils of these plant species were used for the validation of equations from preexistent models, in which observed and estimated values of the biological activity were compared. The regression analysis showed a strong validation of the models, re-stating the trends previously observed. The models were expressed as follows: A, fumigant activity [KT(50(min)) = 10.65-0.076 × 1,8-cineole (%)](p < 0.01; F, 397; R (2), 0.79); B, larval mortality (%)((40 ppm)) = 103.85 + 0.482 × p-cymene (%) - 0.363 × α-pinene (%) - 1.07 × 1,8-cineole (%) (p < 0.01; F, 300; R (2), 0.90). These results confirmed the

Autohydrolysis Pretreatment of Lignocellulosic Biomass for Bioethanol Production

NASA Astrophysics Data System (ADS)

Han, Qiang

Autohydrolysis, a simple and environmental friendly process, has long been studied but often abandoned as a financially viable pretreatment for bioethanol production due to the low yields of fermentable sugars at economic enzyme dosages. The introduction of mechanical refining can generate substantial improvements for autohydrolysis process, making it an attractive pretreatment technology for bioethanol commercialization. In this study, several lignocellulosic biomass including wheat straw, switchgrass, corn stover, waste wheat straw have been subjected to autohydrolysis pretreatment followed by mechanical refining to evaluate the total sugar recovery at affordable enzyme dosages. Encouraging results have been found that using autohydrolysis plus refining strategy, the total sugar recovery of most feedstock can be as high as 76% at 4 FPU/g enzymes dosages. The mechanical refining contributed to the improvement of enzymatic sugar yield by as much as 30%. Three non-woody biomass (sugarcane bagasse, wheat straw, and switchgrass) and three woody biomass (maple, sweet gum, and nitens) have been subjected to autohydrolysis pretreatment to acquire a fundamental understanding of biomass characteristics that affect the autohydrolysis and the following enzymatic hydrolysis. It is of interest to note that the nonwoody biomass went through substantial delignification during autohydrolysis compared to woody biomass due to a significant amount of p-coumaric acid and ferulic acid. It has been found that hardwood which has a higher S/V ratio in the lignin structure tends to have a higher total sugar recovery from autohydrolysis pretreatment. The economics of bioethanol production from autohydrolysis of different feedstocks have been investigated. Regardless of different feedstocks, in the conventional design, producing bioethanol and co-producing steam and power, the minimum ethanol revenues (MER) required to generate a 12% internal rate of return (IRR) are high enough to

Late-Holocene environmental and climatic changes in central part of the Western Sayan Mountain

NASA Astrophysics Data System (ADS)

Grenaderova, Anna; Sharafutdinov, Ruslan

2016-04-01

with most stable hydrological conditions. During this period, the flood waters have supplied the least amount of allochthonous contaminants on the surface of the swamp. On the peatlands, sedge and sedge-moss plant communities were developed. Main plant species which grows in the peatlands are Carex altaica (Gorodk.) V.Krecz, Carex limosa L. Tomentypnum nitens Hedw., Aulacomnium palustre (Hedw.) Schwaegr., Warnstorfia exannulata (B.S.G.) Loeske., Thelypteris palustris Schott, Baeothryon caespitosum (L.) A.Dietr. During the last 500 years an increase of allochthonous contaminants inputs to marsh sediments is observed. In our opinion, the main causes of the increase were reduction the forest area, sharper contrast of summer and winter temperatures and more rapid melting of snow in early summer. The last cause lead to increased levels of floods. Eutrophic-mesotrophic sphagnum communities (Sphagnum warnstorfii Russ., Sph.subsecundum Nees,, Sphagnum angustifolium Jensen., Sph. fuscum (Schimp.) Klinggr.), which are growing at the moment, begin to develop in the peatlands since 500 years ago.