Siliceous microfossil assemblage and accumulation rate variations across the Middle Eocene Climatic Optimum at ODP Site 171-1051

The Middle Eocene Climatic Optimum (MECO; ~ 40 million years ago [Ma]) is one of the most prominent transient global warming events in the Paleogene. Although the event is well documented in geochemical and isotopic proxy records at many locations, the marine biotic response to the MECO remains poorly constrained. We present new high-resolution, quantitative records of siliceous microplankton assemblages from the MECO interval of Ocean Drilling Program (ODP) Site 1051 in the subtropical western North Atlantic Ocean, which are interpreted in the context of published foraminiferal and bulk carbonate stable isotope (d18O and d13C) records. High diatom, radiolarian and silicoflagellate accumulation rates between 40.5 and 40.0 Ma are interpreted to reflect an ~ 500 thousand year (kyr) interval of increased nutrient supply and resultant surface-water eutrophication that was associated with elevated sea-surface temperatures during the prolonged onset of the MECO. Relatively low pelagic siliceous phytoplankton sedimentation accompanied the peak MECO warming interval and the termination of the MECO during an ~ 70 kyr interval centered at ~ 40.0 Ma. Following the termination of the MECO, an ~ 200-kyr episode of increased siliceous plankton abundance indicates enhanced nutrient levels between ~ 39.9 and 39.7 Ma. Throughout the Site 1051 record, abundance and accumulation rate fluctuations in neritic diatom taxa are similar to the trends observed in pelagic taxa, implying either similar controls on diatom production in the neritic and pelagic zones of the western North Atlantic or fluctuations in sea level and/or shelf accommodation on the North American continental margin to the west of Site 1051. These results, combined with published records based on multiple proxies, indicate a geographically diverse pattern of surface ocean primary production changes across the MECO. Notably, however, increased biosiliceous accumulation is recorded at both ODP Sites 1051 and 748 (Southern Ocean) in response to MECO warming. This may suggest that increased biosiliceous sediment accumulation, if indeed a widespread phenomenon, resulted from higher continental silicate weathering rates and an increase in silicic acid supply to the oceans over several 100 kyr during the MECO.

(Table 2) Taxonomic composition of diatoms in dredged samples from the island-side slope of the Kuril-Kamchatka Trench

Studies of diatoms from dredge samples collected on the island slope of the Kuril-Kamchatka Trench have allowed to recognize well-preserved marine diatom assemblages corresponding to assemblages of the followed Oligocene zones: Rhizosolenia oligocaenica (subzone ''a'', 33.6-31 Ma), Cavitatus rectus (29.6-28.2 Ma), and Rocella gelida (28.2-24.0 Ma) as identified in the North Pacific zonal scale. Description of these assemblages and their complete taxonomic composition are presented. Diversity of species together with abundance and degree of preservation of diatoms and accompanying siliceous microorganisms suggests their autochtonous origin and favorable conditions of their development. Assemblages of the Early Oligocene zones Rhizosolenia oligocaenica and Cavitatus rectus recognized in sediments of the outer zone of the Lesser Kuril Ridge (submarine slope of the Shikotan Island) and on the Vityaz' submarine ridge were most probably formed under conditions of a vast shelf, while assemblage of the Late Oligocene zone Rocella gelida encountered only in the region of the Lesser Kuril Ridge formed under more deep-water conditions, presumably, over an island slope. Deepening of the basin in the region of the outer zone of the Lesser Kuril Ridge in Late Oligocene probably reflects one of stages of evolution of the Kuril-Kamchatka Trench.

Aspectos ecológicos da leishmaniose tegumentar americana: 1. estudo experimental da freqüência de flebotomineos a ecótopos artificiais com referência especial a Psychodopygus intermedius

A utilização de galinheiro como modelo experimental na observação do comportamento de Psychodopygus intermedius, desenvolvida na região do Vale do Ribeira, Estado de São Paulo, Brasil, revelou uma estreita associação entre o flebotomíneo e biótopo artificial estudado. Sua maior densidade à margem da mata sugeriu a hipótese de estar adaptado ao efeito marginal. As investigações em ambiente florestal e extraflorestal demonstraram sua nítida preferência pelo último. Diversos aspectos discutidos explicam parcialmente a ocorrência de leishmaniose tegumentar nesse Estado.

Aspectos ecológicos da leishmaniose tegumentar americana: 2. ecótopo artificial como abrigo de Psychodopygus intermedius e observações sobre alimentação e reprodução sob influência de fatores físicos naturais

As observações levadas a cabo em um galinheiro experimental mostraram que Psychodopygus intermedius tem a capacidade de nele abrigar-se. Para se chegar a este resultado, a metodologia utilizada consistiu na coleta total diurna e exame do estado de alimentação e digestão sangüínea dos Ps. intermedius como parâmetro da sua maior ou menor permanência no ecótopo estudado. Além disso, observou-se paralelamente, os tempos para o repasto sangüíneo, digestão completa, oviposição, sobrevivência e cópula sob a influência direta dos fatores físicos naturais. A importância epidemiológica dos resultados reside em novas elucidações experimentais sobre a viabilidade da transmissão da leshmaniose tegumentar ocorrer em ambiente domiciliar.

Aspectos ecológicos da leishmaniose tegumentar americana: 3. Observações naturais sobre o ritmo diário de Psychodopygus intermedius em ambiente florestal e extraflorestal

Pela primeira vez se determina a atividade diária de Psychodopygus intermedius em ambiente florestal residual e extraflorestal, em Pariquera-Açú, Região do Vale do Ribeira, Estado de São Paulo, Brasil. A análise final revelou ter esse flebotomíneo atividade noturna nos dois ambientes. Contudo, houve divergência quanto ao pico de atividade máxima que oscilou entre 20 e 02 horas. Persistiu também a sua predominância no ambiente extraflorestal. Por outro lado, uma acentuada preferência pelo homem parece ter influenciado sua dispersão, pois demonstrou ser ubiquitária. A importância do evento reside na possibilidade de haver uma estreita associação alimentar Ps. intermedius-Homem. Subsequente, a infecção leishmaniótica poderá ocorrer ao nível do domicílio.

Ecological aspects of American cutaneous leishmaniasis: 4. Observations on the endophilic behavior of the sandfly and the vectorial role of Psychodopygus intermedius in the Ribeira Valley region of the S.Paulo State, Brazil

The invasive tendency of Psychodopygus intermedius in the home environment, observed initially by Forattini et al. (1976), has now been confirmed by the demonstration of its high endophilic ability and by the use of human residences for shelter. Populations such as Lutzomyia migonei and Pintomyia fischeri were also present in that environment, though their low densities registered during this investigation could be an indication of their poor ability to overcome the barriers raised by the artificial environment. An objective epidemiological analysis based on the variables here given showed that human infection takes place in the extraforest environment, and the principal vectorial function falls, without doubt, on P. intermedius.

Description of the egg of Anopheles (Anopheles) intermedius (Peryassu, 1908) (Diptera: Culicidae) by scanning electron microscopy

The egg of Anopheles (Anopheles) intermedius (Peryassu, 1908) is described and illustrated with scanning electron micrographs. Literature data on An. (Ano.) maculipes (Theobald, 1903) is provided

Deep sea fishes from the Gulf of Mexico, with the description of a new species, Squalogadus intermedius (Macrouroididae)

v.39:no.29(1959)

Variability and genetic differentiation among Anopheles (Ano.) intermedius Chagas, 1908 and Anopheles (Ano.) mattogrossensis Lutz & Neiva, 1911 (Diptera: Culicidae) from the Brazilian Amazon

Anopheles (Anopheles) intermedius and Anopheles (Ano.) mattogrossensis are Brazilian anopheline species belonging to the scarcely studied Anopheles subgenus. Few studies have been done on the genetic differentiation of these species. Both species have been found infected by Plasmodium and are sympatric with other anopheline species from the Nyssorhynchus subgenus. Eighteen enzymatic loci were analyzed in larval specimens of An. intermedius and An. mattogrossensis aiming to estimate the variability and genetic differentiation between these species. An. mattogrossensis population showed higher genetic variability (P = 44.4 and Ho = 0.081 ± 0.031) than that of An. intermedius (P = 33.3 and Ho = 0.048 ± 0.021). Most analyzed loci showed genotypic frequencies according to Hardy-Weinberg equilibrium, except for LAP1 and LAP2 in An. intermedius, and EST1 and PGM loci in An. mattogrossensis. The genetic distance between these species (D = 0.683) was consistent with the inter-specific values reported for Anopheles subgenus. We verified that the polymorphism and heterozygosity percentile values found in both species and compared to those in the literature, showed no relation between the level of isozyme variability and geographical distribution. The low variability found in these two species is probably more related to the niche they occupy than to their geographic distribution.

Incrimination of Anopheles (Anopheles) intermedius Peryassú, An. (Nyssorhynchus) nuneztovari Gabaldón, An. (Nys.) oswaldoi Peryassú as natural vectors of Plasmodium falciparum in French Guiana

Anopheles darlingi Root is the major vector of human malaria in the Neotropics and has been considered to be the sole malaria vector in French Guiana. The presence of other potential vectors suggests that malaria may be transmitted by other species under certain conditions. From 2006-2011, all anopheline specimens collected from 11 localities were assayed to determine if the Plasmodium circumsporozoite protein was present. In addition to An. darlingi, we found Anopheles oswaldoi, Anopheles intermedius and Anopheles nuneztovari specimens that were infected with Plasmodium sp. Further investigations on the behaviour and ecology of An. oswaldoi, An. intermedius and An. nuneztovari are necessary to determine their role in malaria transmission in French Guiana.

Mechanisms of successful amoxicillin prophylaxis of experimental endocarditis due to Streptococcus intermedius.

Prophylaxis with amoxicillin (40 mg/kg) was studied in rats with aortic valve vegetations. Bacteria on the valves were quantitated early (10 min to 6 hr) and late (three days) after intravenous challenge with tolerant Streptococcus intermedius. Amoxicillin reduced by 40% the number of bacteria per valve 10 min after intravenous challenge with 10(5) S. intermedius (P less than .05) and by 74% the incidence of endocarditis three days thereafter (P less than .0001). Bacterial multiplication started 2 hr after challenge in control rats, whereas bacteria disappeared in 6 hr in amoxicillin-treated rats. Intravenous penicillinase 30 min after challenge abolished successful amoxicillin prophylaxis, a result demonstrating the necessity of prolonged growth inhibition for protection. Growth inhibition for 18 hr (two subsequent amoxicillin doses) was necessary for protection after intravenous challenge with 10(5) S. intermedius. Thus, in the absence of bacterial killing, inhibition of valvular colonization by amoxicillin was not as important a mechanism of endocarditis prophylaxis as was prolonged inhibition of bacterial growth, which allowed adherent bacteria to be cleared from the valves.

The neurochemically diverse intermedius nucleus of the medulla as a source of excitatory and inhibitory synaptic input to the nucleus tractus solitarii

Sensory afferent signals from neck muscles have been postulated to influence central cardiorespiratory control as components of postural reflexes, but neuronal pathways for this action have not been identified. The intermedius nucleus of the medulla (InM) is a target of neck muscle spindle afferents and is ideally located to influence such reflexes but is poorly investigated. To aid identification of the nucleus, we initially produced three-dimensional reconstructions of the InM in both mouse and rat. Neurochemical analysis including transgenic reporter mice expressing green fluorescent protein in GABA-synthesizing neurons, immunohistochemistry, and in situ hybridization revealed that the InM is neurochemically diverse, containing GABAegric and glutamatergic neurons with some degree of colocalization with parvalbumin, neuronal nitric oxide synthase, and calretinin. Projections from the InM to the nucleus tractus solitarius (NTS) were studied electrophysiologically in rat brainstem slices. Electrical stimulation of the NTS resulted in antidromically activated action potentials within InM neurons. In addition, electrical stimulation of the InM resulted in EPSPs that were mediated by excitatory amino acids and IPSPs mediated solely by GABA(A) receptors or by GABA(A) and glycine receptors. Chemical stimulation of the InM resulted in (1) a depolarization of NTS neurons that were blocked by NBQX (2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonoamide) or kynurenic acid and (2) a hyperpolarization of NTS neurons that were blocked by bicuculline. Thus, the InM contains neurochemically diverse neurons and sends both excitatory and inhibitory projections to the NTS. These data provide a novel pathway that may underlie possible reflex changes in autonomic variables after neck muscle spindle afferent activation.

Condition factor of Astyanax intermedius Eigenmann, 1908 (OSTEICHTHYES, CHARACIDAE) parasitised by Paracymothoa astyanaxi Lemos de Castro, 1955 (CRUSTACEA, CYMOTHOIDAE) in the Grande River, Serra do Mar State Park - Santa Virgínia Unit, São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)