bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability of filtration and food assimilation rates, respiratory activity and multixenobiotic resistance (MXR) mechanism in the mussel Perna perna under lead influence
Authors: PESSATTI M. L. , RESGALLA JR. C. , REIS Fo. R. W. , KUEHN J. , SALOMÃO L. C. , FONTANA J. D.
Published: April 2005

The economic importance that myticulture is conquering in Santa Catarina State (South of Brazil) explains the crescent search for new coastal sites for farming. Physiological and biochemical studies of the mussel Perna perna are important to the establishment of methodologies for program assessment and environmental monitoring, allowing to infer about site quality and possible influences of xenobiotic agents on coastal areas. In order to evaluate effects caused by lead poisoning (1.21 mumol.L-1), the mussels were maintained at constant temperature (25ºC) and fed with Chaetoceros gracilis for 15 days. The control group was acclimatized in sea water 30‰. At the end of this period time, physiological measurements were carried out along with statistic analysis for filtration rates, lead assimilation and overall respiratory activity. The mechanism of multixenobiotic resistance (MXR) was particularly evaluated in standardized gill fragments using rhodamine B accumulation and its quantification under fluorescence optical microscopy. Regarding the control group, results had shown that the mussels maintenance in a lead-poisoned environment caused higher filtration rates (1.04 and 2.3 and L.h-1.g-1; p < 0.05) and lower assimilation rates (71.96% and 54.1%, respectively). Also it was confirmed a lesser rhodamine B accumulation in the assays under influence of lead, suggesting that this metal induces the MXR mechanism expression in mussel P. perna. These results indicate that such physiological and biochemical alterations in the mussels can modify the energy fluxes of its metabolism, resulting in possible problems on the coastal systems used as cultivating sites.
Hemocyte types and total and differential counts in unparasitized and parasitized Anastrepha obliqua (Diptera, Tephritidae) larvae
Authors: SILVA J. E. B. , BOLELI I. C. , SIMÕES Z. L. P.
Published: April 2005

The hemocyte types, in addition to total and differential hemocyte counts were studied in parasitized and unparasitized Anastrepha obliqua larvae at the beginning and at the end of the third instar. In both developmental phases, in parasitized and unparasitized larvae, prohemocytes, plasmatocytes, granulocytes, adipohemocytes, spherulocytes and oenocytoids cells were observed. Mitotic figures indicate prohemocytes as stem cells. Prohemocytes, plasmatocytes and granulocytes are the most numerous cells in the hemolymph of A. obliqua. Difference in the total number of hemocytes was observed between unparasitized and parasitized larvae at the end of the third instar, but not at the beginning.
Spatial and temporal variation in densities of chironomid larvae (Diptera) in two lagoons and two tributaries of the upper Paraná River floodplain, Brazil
Authors: HIGUTI J. , TAKEDA A. M.
Published: April 2005

Chironomid larvae were collected and abiotic variables measured at monthly intervals at 21 sampling stations in two lagoons (Guaraná and Patos) and two tributaries (Baía and Ivinheima) of the Upper Paraná River floodplain. The genera Procladius, Chironomus, Goeldichironomus, and Polypedilum were dominant in the lagoons and in the Baía River, while Cryptochironomus and Lopescladius were more dominant in the Ivinheima River. The similarity in the generic composition of the chironomids of the lagoons and the Baía River is probably due to the fact that this river presents hydrodynamic characteristics similar to those of the lagoons. The results obtained suggest that the hydrodynamics of these environments are the main factor determining spatial variation in the chironomid fauna. This is intuitively clear, as this factor itself determines sediment type, quantity of organic matter and presence or absence of aquatic macrophytes. However, on a seasonal scale, the flood pulse seems to be the main controlling factor of the temporal variation in densities and dominance of chironomid larvae. Given that this factor has a large influence on the temporal dynamics of several limnological variables, this is again a logical correlation. Our results suggest a strong relationship between the variations in the chironomid community and fluctuations in limnological characteristics.
Geostatistics as a tool to improve sampling and statistical analysis in wetlands: a case sudy on dynamics of organic matter distribution in the Pantanal of Mato Grosso, Brazil
Authors: NOGUEIRA F. , COUTO E. G. , BERNARDI C. J.
Published: April 2005

The Pantanal of Mato Grosso presents distinct landscape units: permanently, occasionally and periodically flooded areas. In the last ones, sampling is especially difficult due to the high heterogeneity occurring inter and intrastratas. This paper presents a comparison of different methodological approaches showing that they can influence decisively the knowledge of distribution organic matter dynamics. In such an area in order to understand the role of the flood pulse in the distribution dynamics of organic matter in a wetland at the Pantanal, we considered that there is spatial dependence between points. This consideration contradicts the classical statistic principle that focuses on the aleatority, and allowed the obtainment of a larger volume of information from a minor sampling effort, which means better performance, with time and money economy.
Gonad characterization and reproductive cycle of Collisella subrugosa (Orbigny, 1846) (Gastropoda: Acmaeidae) in the Northeastern Brazil
Authors: ROCHA-BARREIRA C. A.
Published: April 2005

Gonad characteristics and reproductive cycle in the acmaeid Collisella subrugosa from Northeastern Brazil were investigated. The individuals were collected monthly from February 1993 to April 1994 at Farol do Mucuripe Beach, Fortaleza, Ceará, Brazil. There is no external characteristic on the shell and the soft body structures except the gonad that allows sex differenciation. The gonad of limpet Collisella subrugosa showned four stages (1) "partially ripe", (2) "ripe", (3) "partially spawned" and (4) "spawned", stages. The reproductive cycle is continous, with the maturation and spawning running parallelly in this population. The temperature was constant during the study period and it did not seem to be important to induce the spawning. The salinity had a weak negative correlation with the spawn process.
Distance from roads and cities as a predictor of habitat loss and fragmentation in the caatinga vegetation of Brazil
Authors: SANTOS A. M. , TABARELLI M.
Published: April 2005

Roads and cities represent huge sources of degradation for adjacent ecosystems regarding nutrient cycling, energy, water flow and species composition. In this study we test the hypothesis that distance from roads and cities is associated with habitat loss and fragmentation in the caatinga vegetation- a dry forest to scrub vegetation that covers ca. 736,000 km² of northeast Brazil. The study site comprised a 2,828.8 km² piece (64 km x 44.2 km) of Xingó region (09°36'S, 37°50'W), which is located between the States of Alagoas and Sergipe. Based on satellite imagery we mapped the remaining vegetation, 145 km of paved roads and the seven small-sized cities set in the study site. A positive correlation was found between the combined distance from roads and cities and the percentage of remaining vegetation as it dropped from 18% at 12 km distant to 5.9% at 1 km distant from cities and roads. Thus, remaining vegetation was reduced by one third near cities and roads. A positive correlation was also found between distance from cities and roads and the percentage of fragments larger than 200 ha, which ranged from 3.6% (within 3 km distance class) to 23.3% (15 km distance class) of all fragments. Our results suggest a road/city-effect zone of 12 to 15 km width, over which habitat loss and fragmentation extend throughout the caatinga vegetation. These findings should be considered in the regional polices for biodiversity conservation and economic development of the caatinga region.
Mesh size and bird capture rates in Mato Grosso do Sul State, Brazil
Authors: Piratelli A.
Published: April 2005

Mist-nets alternating 36-mm and 61-mm mesh in woods and low vegetation of "cerrado" (Brazilian savanna) tested bird-capture efficiency relative to bird length and mass. Of 1,296 birds captured and 102 species, 785 (93 species) were with 36-m mesh and 511 (69 species) with 61-mm mesh. The 61-mm mesh improved capture rates only for some larger species; so, in general, 36-mm mesh mist-nets are more appropriate for field work in "cerrado" areas.
Helminths infecting Mabuya dorsivittata (Lacertilia, Scincidae) from a high-altitude habitat in Itatiaia National Park, Rio de Janeiro State, Southeastern Brazil
Authors: Rocha C. F. D. , Vrcibradic D. , Vicente J. J. , Cunha-Barros M.
Published: April 2005

We analysed the helminth fauna associated with the lizard Mabuya dorsivittata (Scincidae) from a high-altitude area in Itatiaia National Park, Rio de Janeiro State, Brazil. Of the 16 lizards examined, 12 (75%) were infected by at least one helminth. Only two helminth species were found: Physaloptera retusa and Skrjabinodon spinosulus (Nematoda), the former with a prevalence of 68.8% and a mean infection intensity of 3.6 ± 2.8 and the latter with a prevalence of 56.3% and a mean infection intensity of 2.6 ± 2.6. The helminth fauna of the studied population of Mabuya dorsivittata was considerably poorer than those of other previously studied populations of congeners.
Rotifers of the upper Paraná River floodplain: additions to the checklist
Authors: Serafim M. Jr , Bonecker C. C. , Rossa D. C. , Lansac-Tôha F. A. , Costa C. L.
Published: April 2005

Rotifers present a high diversity in freshwater ecosystems. This study registered 11 genera and 42 species, new records for the Upper Paraná River floodplain. These results showed an increase in rotifer diversity in this ecosystem from 184 to 230 species. Among them some were registered only in the rivers and others in the lagoons. Thirty-seven species occurred in the littoral zone and 34 species in the pelagic; 3 species were registered only in the former zone and 2 species only in the latter. The lagoons presented the greatest richness, probably because of the greater stability, low current velocity, and the extensive aquatic macrophyte banks in the littoral zone of these environments as compared to those of the rivers. The highest number of species in the littoral habitats occurred due to the greater influence of shoreline vegetation, which allows greater habitat diversification. This fact contributed to the occurrence of non-planktonic species in the zooplankton samples.
Systematic relations among Philornis Meinert, Passeromyia Rodhain & Villeneuve and allied genera (Diptera, Muscidae)
Authors: Couri M. S. , Carvalho C. J. B.
Published: April 2005

Passeromyia Rodhain & Villeneuve and Philornis Meinert are the only known Muscidae whose larvae are parasites of birds. Passeromyia is known from the Old World and Philornis from the New World. Opinions on the relations between these two genera and their systematic positions among the Muscidae have varied. This survey aims to clear the discussion on the relations of Passeromyia, Philornis, and of some allied genera and give an overview of the classification of the Muscidae based on cladistic methodology. Thirty-two terminal taxa (2 of them outgroups) were analysed based on 54 characters. The cladistic analysis, carried out using Hennig86, resulted in 1 minimal tree (length 373), with a consistency index of 71 and a retention index of 85. Philornis and Passeromyia belong to a monophyletic group, supported by a synapomorphy, the presence of a cocoon, enclosing the pupa. The phylogenetic relationships found in this group are: (Muscina (Philornis (Phaonina ((Fraserella, Passeromyia) (Synthesiomyia (Calliphoroides, Reinwardtia)))))). Other probable monophyletic muscid groups, like Muscinae (with Stomoxyini and Muscini) and Coenosiinae (with Limnophorini and Coenosiini) are also discussed. Phylogenetic patterns within Reinwardtinae and Dichaetomyiinae could be explained by a Gondwana distribution.
Expression of Sec61alpha in F9 and P19 teratocarcinoma cells after retinoic acid treatment
Authors: Ferreira L. R. , Velano C. E. E. , Braga E. C. , Paula C. C. , Martélli-Junior H. , Sauk J. J.
Published: April 2005

Nascent procollagen peptides and other secretory proteins are transported across the endoplasmic reticulum (RE) membrane through a protein-conducting channel called the translocon. Sec61alpha, a multispanning membrane translocon protein, has been implicated as essential for translocation of polypeptides chains into the cisterns of the ER. However, it is not known whether Sec61alpha is ubiquitously expressed in collagen producing teratocarcinoma cells. Furthermore, the production, expression, and utilization of Sec61alpha may depend on the cell differentiation stage. Stem cells from many cultured teratocarcinoma cell lines such as F9 and P19 cells are capable of differentiation in response to low retinoic acid concentrations. This differentiation of the tumorigenic stem cells results in tumorigenicity loss. For this study, mouse F9 and P19 teratocarcinoma cells were grown in culture medium treated with or without retinoic acid. Expression of Sec61alpha was determined by reverse trancriptase polimerase chain reaction (RT-PCR). In untreated conditions, F9 cells expressed undetected Sec61alpha amounts. It was also demonstrated that Sec61alpha expression is stimulated in F9 cells after retinoic acid treatment for 72 hours. No changes were found in Sec61alpha expression in P19 cells after retinoic acid treatment. These data indicate that the expression of Sec61alpha is enhanced with retinoic acid induced differentiation of F9 teratocarcinoma cells.
Parotocinclus planicauda, a new species of the subfamily Hypoptopomatinae from Southeastern Brazil (Ostariophysi: Loricariidae)
Authors: Garavello J. C. , Britski H. A.
Published: April 2005

Parotocinclus planicauda, a new species from a tributary of the Doce River drainage in Minas Gerais State, Brazil, is distinguished from all other species of the genus by the presence of a caudal peduncle almost quadrangular in cross section; the anterior position of the adipose fin, close to the dorsal fin insertion; and very small orbits. A key to the Parotocinclus species of eastern Brazilian coastal rivers south of the São Francisco River is provided.
Pathogenicity of Bacillus thuringiensis isolated from two species of Acromyrmex (Hymenoptera, Formicidae)
Authors: Pinto L. M. N. , Azambuja A. O. , Diehl E. , Fiuza L. M.
Published: April 2005

The control of Acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. A possibility was to control them using the bacterium Bacillus thuringiensis (Bt) that characteristically produces insecticidal crystal proteins (ICPs). The ICPs have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. This paper describes an attempt to isolate Bt from ants of two Acromyrmex species, to evaluate its pathogenicity towards these ants, and to test isolates by PCR. Bacterial isolates of Bt obtained from A. crassispinus and A. lundi have been assayed against A. lundi in the laboratory. The bioassays were carried out in BOD at 25°C, with a 12-hour photoperiod, until the seventh day after treatment. The Bt isolates obtained were submitted to total DNA extraction and tested by PCR with primers specific to cry genes. The results showed Bt presence in 40% of the assessed samples. The data from the in vivo assays showed a mortality rate higher than 50% in the target population, with the Bt HA48 isolate causing 100% of corrected mortality. The PCR results of Bt isolates showed a magnification of DNA fragments relative to cry1 genes in 22% of the isolates, and cry9 in 67%. Cry2, cry3, cry7, and cry8 genes were not detected in the tested samples, and 22% had no magnified DNA fragments corresponding to the assessed cry genes. The results are promising not only regarding allele identification in new isolates, but also fort the assays aimed at determining the Bt HA48 LC50's, which can eventually be applied in controlling of Acromyrmex leaf-cutting ants.
Patterns of infestation by chigger mites in four diurnal lizard species from a restinga habitat (Jurubatiba) of Southeastern Brazil
Authors: Cunha-Barros M. , Van Sluys M. , Vrcibradic D. , Galdino C. A. B. , Hatano F. H. , Rocha C. F. D.
Published: April 2005

We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity) of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation) of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62); 100%; 20.9 + 9.3 in M. agilis (n = 7); 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12); and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21). Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02). For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.
Pollen spectrum of honey produced in cerrado areas of Minas Gerais State (Brazil)
Authors: Bastos E. M. A. F. , Silveira V. M. , Soares A. E. E.
Published: April 2005

The pollen spectra of honey samples collected in five apiaries situated near cerrado areas in Minas Gerais State, Brazil, were studied from April 1996 to April 1998 in order to establish the contribution of different plant species in pollen or nectar production The honey samples were characterized by the following native species: Astronium sp., Alternanthera sp., Schinus sp., and Serjanea sp. The pollinic participation percentage of those species was related to the degree of preservation in the areas.
Ecological roles of natural products of the Brazilian red seaweed Laurencia obtusa
Authors: Pereira R. C. , da Gama B. A. P. , Teixeira V. L. , Yoneshigue-Valentin Y.
Published: April 2005

Laboratory and field experiments were performed to assess the ecological roles of natural products produced by the Brazilian red seaweed Laurencia obtusa. Laboratory assays revealed that the natural concentration of the crude organic extract of L. obtusa significantly inhibited feeding by two herbivores: the crab Pachygrapsus transversus and the sea urchin Lytechinus variegatus. It was verified that this chemically defensive action was due to halogenated sesquiterpenoid elatol, found to be the major natural product of this red seaweed. In addition, it was verified that the antifouling property of the chemicals produced by L. obtusa could make this red alga less attractive for fish grazing. Direct protection against two herbivore species and indirect protection against herbivory by fouling inibition constitute evidence that the major natural product from Brazilian L. obtusa plays multiple environmental roles, thereby increasing the adaptive value of these metabolites. On the other hand, the evidence reinforces the idea that marine natural products may have different functions in the sea.
Macroecological analyses support an overkill scenario for late Pleistocene extinctions
Authors: Diniz-Filho J. A. F.
Published: April 2005

The extinction of megafauna at the end of Pleistocene has been traditionally explained by environmental changes or overexploitation by human hunting (overkill). Despite difficulties in choosing between these alternative (and not mutually exclusive) scenarios, the plausibility of the overkill hypothesis can be established by ecological models of predator-prey interactions. In this paper, I have developed a macroecological model for the overkill hypothesis, in which prey population dynamic parameters, including abundance, geographic extent, and food supply for hunters, were derived from empirical allometric relationships with body mass. The last output correctly predicts the final destiny (survival or extinction) for 73% of the species considered, a value only slightly smaller than those obtained by more complex models based on detailed archaeological and ecological data for each species. This illustrates the high selectivity of Pleistocene extinction in relation to body mass and confers more plausibility on the overkill scenario.
New cladoceran records from Lake Paranoá, Central Brazil
Authors: Elmoor-Loureiro L. M. A. , Mendonça-Galvão L. , Padovesi-Fonseca C.
Published: April 2005

The zooplanktonic community of Lake Paranoá has been studied for more than thirty years. Until 1998, when it was considered eutrophic, only three cladoceran species were known from the reservoir. Since 1999, when Lake Paranoá underwent intentional flushing, definite changes in species diversity and composition were identified. At the same time, exploratory studies on littoral cladoceran species were being done. The present study aims to provide additional information on the cladoceran species composition of Lake Paranoá. Seven new species records are presented, four of them also representing the first record from the Federal District (Brasília). The population previously considered as belonging to Bosmina longirostris was reconsidered and re-identified as Bosmina freyi. Figures and comments on species taxonomy and distribution are also provided.
Spatial distribution and interaction of four species of the catfish genus Hypostomus Lacépède with bottom of Rio São Francisco, Canindé do São Francisco, Sergipe, Brazil (Pisces, Loricariidae, Hypostominae)
Authors: Garavello J. C. , Garavello J. P.
Published: April 2005

The large catfishes, genus Hypostomus Lacépède, are common species in almost all freshwater environments of South America. The behavior of specimens from the species Hypostomus alatus, Hypostomus francisci, Hypostomus cf. wuchereri, and Hypostomus sp., from the region downstream from the Xingó Hydroelectric Power Dam, located in Canindé do São Francisco on the Rio São Francisco, were observed. Morphological characters collected from preserved specimens were also studied in the laboratory, in order to shed light on interactions between those fishes and the river bottom. In addition, the formulation of Gatz (1979) was applied to better explain the environmental interactions of Hypostomus species. This study revealed that the fishes utilize their suckers, through a mouth equipped with an oral disk, as well as the pectoral, pelvic, and caudal fins areas, to interact with the rocky river-bottom. The comb-toothed inferior mouth of the Hypostomus showed itself able to grasp green algae on the river bottom. With the help of the oral disk and sucker mouth, which anchor the fishes, in conjunction with the arched design of pectoral and pelvic fin spines, they are also able to remain upright while exploring this substratum. In addition, their large, concave caudal-fin is associated with fast locomotion over short distances. This combination of characteristics allow these fish to live on the bottom of large South American rivers.
Cannibalism as the main feeding behaviour of tucunares introduced in Southeast Brazil
Authors: Gomiero L. M. , Braga F. M. S.
Published: April 2005

Individuals of its own genus were the main food item of two species of tucunares (Cichla cf. ocellaris and Cichla monoculus) introduced into the Volta Grande Reservoir. The abundance of adult tucunares may cause intra-specific competition, possibly leading to the high cannibalism rates found.
Palm harvesting affects seed predation of Euterpe edulis, a threatened palm of the Brazilian Atlantic Forest
Authors: Pizo M. A. , Vieira E. M.
Published: April 2005

The palm tree Euterpe edulis is endemic to the Atlantic Forest, where it constitutes an economically important forest product. The often unplanned and illegal harvesting of palm hearts has led to drastic reductions in the populations of E. edulis in many areas where this palm used to be the dominant understorey tree species. We investigated the effects of harvesting on seed and seedling predation of E. edulis. We tested the predictions of the dominance-predation hypothesis according to which predator satiation leads to an inverse relationship between the amount of predation and the dominance of a tree species. During two consecutive years, seeds were set experimentally on an unharvested (> 250 adult palms/ha) and a neighboring harvested site (few, if any, adult palms) located in the Atlantic Forest of SE Brazil. Seedling mortality was studied at both sites for a six-month period in each of two consecutive years. Seed predation caused by rodents was higher at the harvested site, while insects caused more damage to seeds placed at the unharvested site. The proportion of seeds preyed upon by rodents varied annually, while insect predation did not. Seedling mortality did not differ between harvested and unharvested sites. The dominance-predation hypothesis was confirmed for generalist rodent seed predators, but not for specialist insect predators. This result shows that density-dependent mortality, not only at the individual level but also at the population-level scale, is a function of the class of predators and their types of foraging behavior.
Ultramorphology and histochemistry of fat body cells from last Instar larval of the Pachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)
Authors: Zara F. J. , Caetano F. H.
Published: April 2005

The fat body cells of Pachycondyla (=Neoponera) villosa are disposed in a single layer between the cuticle and the digestive tract, forming a group of cells enclosed by a thin membrane. Histological studies have revealed three different cellular types: trophocyte (more abundant), urate, (located among the trophocytes), and oenocyte (the scarcest), usually observed laying near the cuticle. Histochemically, the trophocytes showed a positive reaction for basic proteins in the nucleus and cytoplasm, as well as a strong positive reaction in the cytoplasmic granules. The test for carbohydrates showed a strong positive reaction throughout the cytoplasm, while the test for lipids was positive for the cytoplasmic vesicles. The urate cells showed a positive reaction for basic proteins in the nucleus and in the areas of the cytoplasm surrounding the vesicles. These cells did not react to the PAS test or to Sudan Black B. The oenocytes showed a weak positive reaction to PAS and a strong positive reaction to Sudan Black B and Mercuric-bromophenol Blue.
Differential trappability of small mammals in three habitats of Southeastern Brazil
Authors: Vieira M. V. , Grelle C. E. V. , Gentile R.
Published: April 2005

We compared the trappability of marked and unmarked individuals in species of marsupials and rodents of three tropical assemblages of small mammals in Brazil. Two studies used trapping grids, one in cerrado and the other in an Atlantic forest reserve, whereas the study in a rural area used transects. In the two studies using trapping grids, marked animals were frequently more trappable than unmarked ones, but in some species this difference was not significant. In the rural area, marked and unmarked animals did not differ significantly. The number of recaptures per resident animal was higher in the two studies using trapping grids than in the rural area where transects were used. Differences in trappability between the three studies might have been caused by differences not only in trapping design (grids vs. transects), but also in the type of trap used, bait, and habitat. Although differential trappability tends to be considered the rule in small mammals, these results suggest that trappability of marked and unmarked animals may be specific for the particular combination of sampling design, field methods, and habitat under study.
Signal transduction, cell division, differentiation and development: towards unifying mechanisms for pattern formation in plants
Authors: Dornelas Marcelo Carnier
Published: April 2005

The elaboration of plant form and function depends on the ability of a plant cell to divide and differentiate. The decisions of individual cells to enter the cell cycle, maintain proliferation competence, become quiescent, expand, differentiate, or die depend on cell-to-cell communication and on the perception of various signals. These signals can include hormones, nutrients, light, temperature, and internal positional and developmental cues. In recent years, progress has been made in understanding the molecular control of plant pattern formation, especially in the model plant Arabidopsis thaliana. Furthermore, specific genes have been found that are necessary for normal pattern formation and the control of the rates of cell division and differentiation. Cloning of these genes is revealing the molecular basis of plant pattern formation and the key players on plant signal transduction systems.
Transpiration, leaf diffusive conductance, and atmospheric water demand relationship in an irrigated acid lime orchard
Authors: Angelocci Luiz Roberto , Marin Fábio Ricardo , Oliveira Ricardo Ferraz de , Righi Evandro Zanini
Published: April 2005

Leaf vapor diffusive conductance (gl) and transpiration (T) measurements in an irrigated orchard of the acid lime "Tahiti" were carried out in a subtropical climatic condition in the State of São Paulo, Brazil. Measurements were made using steady-state null-balance porometers and were taken throughout the day, on several occasions from February to November, 1998. During September and October, measurements were performed on exposed and shaded young and fully expanded leaves, as well as on old leaves inside the tree canopy. The old leaves showed lower values of gl and T when compared to the other groups. In the other months, measurements were taken only with exposed and shaded fully expanded leaves. The highest values of gl and T were obtained from February to April. For exposed leaves gl was higher from early morning to midday, decreasing thereafter with some oscillation in the afternoon. Shaded leaves produced a pattern of increasing gl and T from 8:00-9:00 a.m. to midday, followed by a decrease when values matched those of the exposed leaves in the afternoon. In April, the first measurement in midmorning showed low gl and T values, increasing sharply in the exposed leaves until midday and then decreasing until the end of the afternoon. Between May and November, gl and T decreased sharply compared to the previous months. Boundary line and regression analysis were used to find the mathematical relationships between mean values of gl for the tree and photosynthetic photons flux density, temperature, and vapor pressure deficit of the air measured in the orchard. Based on this analysis, the reasons for the gl and T diurnal and annual variation patterns are discussed, with emphasis on the effects of atmospheric variables upon stomatal regulation.
Gas exchange and yield response to foliar phosphorus application in Phaseolus vulgaris L. under drought
Authors: Santos Mauro Guida dos , Ribeiro Rafael Vasconcelos , Oliveira Ricardo Ferraz de , Pimentel Carlos
Published: April 2005

This study was conducted to evaluate the effect of foliar Pi application on gas exchange and yield of bean genotypes submitted to a mild water deficit at the pre-flowering stage. In the first experiment, when extra Pi (10 g.L-1) was sprayed on leaves during water stress or during recovery, there was no effect on gas exchange or yield in the A320, Carioca and Ouro Negro genotypes. However, net CO2 assimilation (A) of A320 and Ouro Negro was less affected, but not significantly, than Carioca at the end of the stress, when Pi was supplied five days before water deficit. In the second experiment, two different doses of Pi (10 and 20 g.Pi L-1) were sprayed five days before water deficit on the Carioca genotype. During the last three days of the mild water deficit, A values were significantly higher for the Pi20 treatment when compared to the control plants without extra Pi supply. The intrinsic water use efficiency for plants receiving Pi20 was significantly higher than for the other treatments. In addition, seed dry weight per plant was higher for plants receiving Pi20 dose than for plants with Pi10 and its control.
An infant oral health programme in Goiânia-GO, Brazil: results after 3 years of establishment
Authors: Pereira Marina Batista Borges , Freire Maria do Carmo Matias
Published: April 2005

The objective of this study was to describe the outcomes of an infant oral health programme 3 years after implementation, a programme focused on health education for parents and caries prevention methods for children in a baby clinic. A retrospective cohort study was carried out. The setting was the Infant Oral Health Programme developed at the baby clinic of the State Department of Health, Goiânia-GO, Brazil. The sample comprised 100 children who entered the programme from birth to 12 months and were followed for 2 to 3 years. Variables investigated were caries experience, caries risk, and children's behaviour in the dental clinic. The number of children with caries experience was 1 at the initial visit and 8 after the follow-up. There was a dramatic decrease in the number of children in the high risk group, from 51% at the initial visit to only 1% after 2 to 3 years. Children's behaviour in the dental clinic was according to their psychological development. It was concluded that the Infant Oral Health Programme in Goiânia showed positive outcomes after 3 years of establishment. Further investigations should evaluate the cost-benefit, as well as the effectiveness of the procedures used in the programme.
Morphometric characterization of sexual differences in the rat sublingual gland
Authors: Lima Marta da Cunha , Sottovia-Filho Dagoberto , Cestari Tania Mary , Taga Rumio
Published: April 2005

The presence of morphological differences in the sublingual gland of male and female adult rats was determined by morphometry. Absolute and relative glandular mass was 21% lower and 31% higher, respectively, in females than in males. The fractions of glandular volume occupied by the mixed acini, intercalated ducts and striated ducts did not differ significantly between genders; however, their absolute volume was respectively 29, 42 and 58% higher in males. Despite the differences in the volume of these morphological compartments, the number of cells did not differ significantly between genders, except for the excretory duct compartment, for which a larger number was observed in males. With respect to cell volume, 13, 33 and 47% higher volumes were observed in males for mucous acinar cells and striated and excretory duct cells, respectively, while a 38% higher volume of serous demilune cells was observed for females. The surface-to-volume ratio of acini and striated ducts was respectively 16 and 35% higher in females. Based on these results, we conclude that the sublingual gland of female rats possesses smaller acini, and shorter ducts whose caliber is narrower, smaller mucous acinar and larger serous cells than the ones found in the male gland, indicating the presence of sexual dimorphism as well as suggesting sexual differences in the quality of the secreted product.
Toothbrushing with vegetable oil: a clinical and laboratorial analysis
Authors: Aguiar Alciara Alice de Almeida , Saliba Nemre Adas
Published: April 2005

The dentifrices currently available in the marketplace contain many anticariogenic substances, fluoride and abrasives aimed to better clean the dental surface, remove dental plaque, improve salivary flow and its buffer capacity and reduce colonies of bacteria such as S. mutans, the causative agent of dental caries. The objective of this study was to evaluate the possibility of adequately removing dental plaque using an experimental almond oil dentifrice (Titoil) with no abrasives or antiplaque agents. This study was carried out with 80 volunteers, all of them 18-year-old recruits from the military training school of Araçatuba - SP. Saliva sampling and dental plaque disclosing were undertaken both before and after 28 days of toothbrushing with a low abrasive dentifrice (Group 1: 40 volunteers) or with Titoil (Group 2: 40 volunteers). Statistical analysis of the results revealed that the experimental dentifrice (Titoil) did not interfere with salivary flow and reduced dental plaque more than the low abrasive dentifrice, improved the salivary buffer capacity and decreased salivary S. mutans (Caritest-SM) as much as regular dentifrices. It was concluded that if the dental industry replaces abrasive by vegetable oil in dentifrices, these will be more effective in maintaining oral health and will cause less dental abrasion.
Effect of the diameter on Cu-Al post retention
Authors: Souza Filho Celso Bernardo de , Paulino Silvana Maria , Alfredo Edson , Sousa Neto Manoel Damião de , Vansan Luiz Pascoal
Published: April 2005

This study compared the resistance to removal by traction of abraded cylindrical metal cast posts of Cu-Al (Goldent-LA). The posts had constant length (9 mm) and three different diameters (0.9, 1.3 and 1.7 mm), and were cemented with zinc phosphate cement. The crowns of 36 sound maxillary canines were sectioned, the roots were immersed in resin blocks and the root canals were endodontically treated. The teeth were divided into three groups to be prepared and standardized with the use of a parallelometer with the following burs: Group 1 - Largo n. 2; Group 2 - Largo n. 4; Group 3 - Largo n. 6. The posts were molded with chemically activated resin and after casting they were abraded and their dimensions were confirmed with a digital caliper. After cementation of the posts in the prepared root canals, the samples were kept at 37ºC in distilled water for 7 days and subsequently submitted to the traction test in a universal testing machine (Instron 4444). The results showed no statistical difference between the groups. Diameter variation (0.9 mm, 1.3 mm and 1.7 mm) in abraded cylindrical posts cemented with zinc phosphate did not affect resistance to removal.
Teaching and Safety-Net Hospital Penalization in the Hospital-Acquired Condition Reduction Program
Authors: Serpa Jose A. , Gemeinhardt Gretchen , Arias Cesar A. , Morgan Robert O. , Russell Heidi , Miao Hongyu , Ganduglia Cazaban Cecilia M.
Published: February 2024

Importance

The Hospital-Acquired Condition Reduction Program (HACRP) evaluates acute care hospitals on the occurrence of patient safety events and health care–associated infections. Since its implementation, several studies have raised concerns about the overpenalization of teaching and safety-net hospitals, and although several changes in the program’s methodology have been applied in the last few years, whether these changes reversed the overpenalization of teaching and safety-net hospitals is unknown.

Objective

To determine hospital characteristics associated with HACRP penalization and penalization reversal.

Design, Setting, and Participants

This retrospective cross-sectional study assessed data from 3117 acute care hospitals participating in the HACRP. The HACRP penalization and hospital characteristics were obtained from Hospital Compare (2020 and 2021), the Inpatient Prospective Payment System impact file (2020), and the American Hospital Association annual survey (2018).

Exposures

Hospital characteristics, including safety-net status and teaching intensity (no teaching and very minor, minor, major, and very major teaching levels).

Main Outcomes and Measures

The primary outcome was HACRP penalization (ie, hospitals that fell within the worst quartile of the program’s performance). Multivariable models initially included all covariates, and then backward stepwise variable selection was used.

Results

Of 3117 hospitals that participated in HACRP in 2020, 779 (25.0%) were safety-net hospitals and 1090 (35.0%) were teaching institutions. In total, 771 hospitals (24.7%) were penalized. The HACRP penalization was associated with safety-net status (odds ratio [OR], 1.41 [95% CI, 1.16-1.71]) and very major teaching intensity (OR, 1.94 [95% CI, 1.15-3.28]). In addition, non–federal government hospitals were more likely to be penalized than for-profit hospitals (OR, 1.62 [95% CI, 1.23-2.14]), as were level I trauma centers (OR, 2.05 [95% CI, 1.43-2.96]) and hospitals located in the New England region (OR, 1.65 [95% CI, 1.12-2.43]). Safety-net hospitals with major teaching levels were twice as likely to be penalized as non–safety-net nonteaching hospitals (OR, 2.15 [95% CI, 1.14-4.03]). Furthermore, safety-net hospitals penalized in 2020 were less likely (OR, 0.64 [95% CI, 0.43-0.96]) to revert their HACRP penalization status in 2021.

Conclusions and Relevance

Findings from this cross-sectional study indicated that teaching and safety-net hospital status continued to be associated with overpenalization in the HACRP despite recent changes in its methodology. Most of these hospitals were also less likely to revert their penalization status. A reevaluation of the program methodology is needed to avoid depleting resources of hospitals caring for underserved populations.
Comparison of Vital Sign Cutoffs to Identify Children With Major Trauma
Authors: Gorski Jillian K. , Chaudhari Pradip P. , Spurrier Ryan G. , Goldstein Seth D. , Zeineddin Suhail , Martin-Gill Christian , Sepanski Robert J. , Stey Anne M. , Ramgopal Sriram
Published: February 2024

Importance

Vital signs are essential components in the triage of injured children. The Advanced Trauma Life Support (ATLS) and Pediatric Advanced Life Support (PALS) physiologic criteria are frequently used for trauma assessments.

Objective

To evaluate the performance of ATLS and PALS criteria vs empirically derived criteria for identifying major trauma in children.

Design, Setting, and Participants

This retrospective cohort study used 2021 American College of Surgeons Trauma Quality Improvement Program (TQIP) data contributed by US trauma centers. Included encounters involved pediatric patients (aged <18 years) with severe injury, excluding those who experienced out-of-hospital cardiac arrest, were receiving mechanical ventilation, or were transferred from another facility. Data were analyzed between April 9 and December 21, 2023.

Exposure

Initial hospital vital signs, including heart rate, respiratory rate, and systolic blood pressure (SBP).

Main Outcome and Measures

Major trauma, determined by the Standard Triage Assessment Tool, a composite measure of injury severity and interventions performed. Multivariable models developed from PALS and ATLS vital sign criteria were compared with models developed from the empirically derived criteria using the area under the receiver operating characteristic curve. Validation of the findings was performed using the 2019 TQIP dataset.

Results

A total of 70 748 patients (median [IQR] age, 11 [5-15] years; 63.4% male) were included, of whom 3223 (4.6%) had major trauma. The PALS criteria classified 31.0% of heart rates, 25.7% of respiratory rates, and 57.4% of SBPs as abnormal. The ATLS criteria classified 25.3% of heart rates, 4.3% of respiratory rates, and 1.1% of SBPs as abnormal. Among children with all 3 vital signs documented (64 326 [90.9%]), PALS had a sensitivity of 88.4% (95% CI, 87.1%-89.3%) and specificity of 25.1% (95% CI, 24.7%-25.4%) for identifying major trauma, and ATLS had a sensitivity of 54.5% (95% CI, 52.7%-56.2%) and specificity of 72.9% (95% CI, 72.6%-73.3%). The empirically derived cutoff vital sign z scores had a sensitivity of 80.0% (95% CI, 78.5%-81.3%) and specificity of 48.7% (95% CI, 48.3%-49.1%) and area under the receiver operating characteristic curve of 70.9% (95% CI, 69.9%-71.8%), which was similar to PALS criteria (69.6%; 95% CI, 68.6%-70.6%) and greater than ATLS criteria (65.4%; 95% CI, 64.4%-66.3%). Validation using the 2019 TQIP database showed similar performance to the derivation sample.

Conclusions and Relevance

These findings suggest that empirically derived vital sign criteria strike a balance between the sensitivity of PALS criteria and the specificity of ATLS criteria in identifying major trauma in children. These criteria may help to identify children at greatest risk of trauma-related morbidity and mortality.
Confidentiality for SUD records: Final rule issued
Authors: Knopf Alison
Published: February 2024

A week after the federal Department of Health and Human Services (HHS) issued a final rule liberalizing treatment for opioid use disorder (OUD) in opioid treatment programs, it issued a less patient‐friendly rule. ADAW has written about 400 articles on confidentiality and substance use disorder treatment, an area that has seen continued erosion since 2010 when the government started acceding to claims that requiring a patient to consent to the release of his or her substance use disorder (SUD) treatment information in a digital age (think “Electronic Health Record”) would be just too inconvenient. The most recent step came in the Federal Register issued Feb. 8, which changes the confidentiality rules to align with those of HIPAA. The rule, through the HHS Office for Civil Rights (OCR) and the Substance Abuse and Mental Health Services Administration (SAMHSA), finalized modifications to the Confidentiality of Substance Use Disorder (SUD) Patient Records regulations at 42 CFR part 2 (“Part 2”), which protect the privacy of patients' SUD treatment records. In a press release about the rule, HHS said this: “Specifically, today's final rule increases coordination among providers treating patients for SUDs, strengthens confidentiality protections through civil enforcement, and enhances integration of behavioral health information with other medical records to improve patient health outcomes.”
NIDA: Psilocybin mushroom seizures rose significantly
Authors: Knopf Alison
Published: February 2024

A National Institute on Drug Abuse (NIDA)‐funded study published in the journal Drug and Alcohol Dependence titled
“National and Regional Trends in Seizures of Shrooms (Psilocybin) in the United States, 2017‐2022” reported a significant increase in law enforcement seizures of psilocybin mushrooms, also known as “magic mushrooms” or “shrooms,” in the United States from January 2017 to December 2022. The study is based on data from the White House Office of National Drug Control Policy's (ONDCP)
High Intensity Drug Trafficking Areas (HIDTA) program, which tracks law enforcement seizures in hotspots across the country. Key findings include: