Annual Changes In A Bird Assembly On Artificial Perches: Implications For Ecological Restoration In A Subtropical Agroecosystem

Artificial perches are used in tropical forest restoration projects to increase the dispersal of seeds into restored areas. The ability of perches to enhance seed deposition depends on their ability to attract seed dispersing birds, as well as the correlation between the season of bird visits to perches and the phenology of fruit production in adjacent forests. Using data collected from a large-scale restoration project, we characterized the community of birds that utilize artificial perches over the course of one year. We hypothesized that the structure of a bird assemblage that uses artificial perches is affected by seasonal variation. We aimed to describe the richness, abundance and diversity of a bird assemblage on artificial perches in a subtropical Atlantic forest restoration experiment in Southern Brazil. Richness and abundance estimates of the avian fauna were obtained from eight artificial perches placed in four experimental plots (B2 y-old). Parameters of richness and abundance were compared using ANOVA. The bird assemblage was described using SHE analysis [richness (S), diversity (H’) and evenness (E)], with additional estimates of occurrence and dominance. In total, 451 records of 32 ± 3.16 SD species were obtained. Thraupidae was the most numerous family (nine species, 28.12% of the total). Richness and abundance varied seasonally and were highest during spring and summer. Five migratory species of flycatchers were recorded between spring and early autumn. Perches were ineffective in attracting specialized frugivorous birds, emphasizing that seed dispersal tends to be carried out primarily by generalist omnivores in the initial phase of forest regeneration. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.16

Direct Determination of the Kinetics of Oxygen Diffusion to the Photocytes of a Bioluminescent Elaterid Larva, Measurement of Gas- and Aqueous-Phase Diffusional Barriers and Modelling of Oxygen Supply

We describe the development and use of a direct kinetic technique to determine the time taken for oxygen to diffuse from the external environment into the light-producing cells (photocytes) in the prothorax of bioluminescent larvae of Pyrearinus termitilluminans. This was achieved by measuring the time course of the pseudoflash induced through sequential anoxia followed by normoxia. We have also determined the separate times taken for this oxygen diffusion in gaseous and tissue (predominantly aqueous) phases by using helium and nitrogen as the carrier gas. Of the total time taken for diffusion, that in the gas phase required 613+/-136 ms (mean +/- s.e. m., N=5) whilst that in the aqueous phase required 1313+/-187 ms. These values imply pathlengths of diffusion in the gaseous and aqueous phases of 4.80x10(-)(3)+/-0.53x10(-)(3) and 8. 89x10(-)(5)+/-0.61x10(-)(5 )m, respectively. In addition, the pathlength of gas-phase diffusion was used to derive a parameter relating to the tortuosity of the tracheal system. These values, together with those obtained upon bioluminescent oxygen consumption, have been used to model oxygen supply to the photocyte. From these studies, it would also appear that the modulation of tracheolar fluid levels might be a significant mechanism of control of tissue oxygen levels in at least some insects

Associations between nutrients and foot ulceration in diabetes : a systematic review

We reviewed the literature to evaluate potential associations between vitamins, nutrients, nutritional status or nutritional interventions and presence or healing of foot ulceration in diabetes. Embase, Medline, PubMed, and the Cochrane Library were searched for studies published prior to September 2020. We assessed eligible studies for the association between nutritional status or interventions and foot ulcers. Fifteen studies met the inclusion criteria and were included in this review. Overall, there is a correlation between poor nutritional status and the presence of foot ulceration or a delay in healing. However, there is not enough data to reach conclusions about whether the rela-tionships are causal or only association. Further research is required to test whether any forms of nutritional supplementation improve foot ulcer healing

Measurement of Oxygen Partial Pressure, its Control During Hypoxia and Hyperoxia, and its Effect upon Light Emission in a Bioluminescent Elaterid Larva

This study investigates the respiratory physiology of bioluminescent larvae of Pyrearinus termitilluminans in relation to their tolerance to hypoxia and hyperoxia and to the supply of oxygen for bioluminescence. The partial pressure of oxygen (P(O2)) was measured within the bioluminescent prothorax by in vivo electron paramagnetic resonance (EPR) oximetry following acclimation of larvae to hypoxic, normoxic and hyperoxic (normobaric) atmospheres and during periods of bioluminescence (during normoxia). The P(O2) in the prothorax during exposure to an external P(O2) of 15.2, 160 and 760 mmHg was 10.3+/-2.6, 134+/-0.9 and 725+/-73 mmHg respectively (mean +/- s.d., N=5; 1 mmHg=0.1333 kPa). Oxygen supply to the larvae via gas exchange through the spiracles, measured by determining the rate of water loss, was also studied in the above atmospheres and was found not to be dependent upon P(O2). The data indicated that there is little to no active control of extracellular tissue P(O2) within the prothorax of these larvae. The reduction in prothorax P(O2) observed during either attack-response-provoked bioluminescence or sustained feeding-related bioluminescence in a normoxic atmosphere was variable, but fell within the range 10-25 mmHg. The effect of hypoxic atmospheres on bioluminescence was measured to estimate the intracellular P(O2) within the photocytes of the prothorax. Above a threshold value of 50-80 mmHg, bioluminescence was unaffected by P(O2). Below this threshold, an approximately linear relationship between P(O2) and bioluminescence was observed. Taken together with the extracellular P(O2) measurements, this suggests that control of P(O2) within the photocyte may occur. This work establishes that EPR oximetry is a valuable technique for long-term measurement of tissue P(O2) in insects and can provide valuable insights into their respiratory physiology. It also raises questions regarding the hypothesis that bioluminescence can have a significant antioxidative effect by reduction of prothorax P(O2 )through oxygen consumption

An actin molecular treadmill and myosins maintain stereocilia functional architecture and self-renewal

We have previously shown that the seemingly static paracrystalline actin core of hair cell stereocilia undergoes continuous turnover. Here, we used the same approach of transfecting hair cells with actin–green fluorescent protein (GFP) and espin-GFP to characterize the turnover process. Actin and espin are incorporated at the paracrystal tip and flow rearwards at the same rate. The flux rates (∼0.002–0.04 actin subunits s−1) were proportional to the stereocilia length so that the entire staircase stereocilia bundle was turned over synchronously. Cytochalasin D caused stereocilia to shorten at rates matching paracrystal turnover. Myosins VI and VIIa were localized alongside the actin paracrystal, whereas myosin XVa was observed at the tips at levels proportional to stereocilia lengths. Electron microscopy analysis of the abnormally short stereocilia in the shaker 2 mice did not show the characteristic tip density. We argue that actin renewal in the paracrystal follows a treadmill mechanism, which, together with the myosins, dynamically shapes the functional architecture of the stereocilia bundle

Aumento do estresse oxidativo após hipotermia em ratos com pancreatite induzida por ceruleína

BACKGROUND: Hypothermia is a frequent event in severe acute pancreatitis (AP) and its real effects on the normal pancreas have not been well demonstrated. Moreover, neither have its effects on the outcome of acute pancreatitis been fully investigated. One hypothesis is that oxidative stress may be implicated in lesions caused or treated by hypothermia. AIM OF THE STUDY: To investigate the effect of hypothermia in cerulein-induced acute pancreatitis (CIAP) in rats and the role played by oxidative stress in this process. METHODS: Male Wistar rats were divided into hypothermic and normothermic groups. Hypothermia was induced with a cold mattress and rectal temperature was kept at 30ºC for one hour. Acute pancreatitis was induced with 2 doses of cerulein (20 ìg/kg) administered at a one-hour interval. Serum amylase, pancreas vascular permeability by Evan's blue method, pancreas wet-to-dry weight ratio and histopathology were analyzed in each group. RESULTS: When compared with normothermic rats, hypothermic animals, with cerulein-induced acute pancreatitis, showed higher levels of pancreatic vascular permeability (p < 0.05), pancreas wet-to-dry weight ratio (p = 0.03), and histologically verified edema (p < 0.05), but similar serum amylase levels. The hypothermic group showed a higher oxidized-reduced glutathione ratio than the normothermic group. CONCLUSION: Moderate hypothermia produced a greater inflammatory response in established acute pancreatitis induced by cerulein in rats. Moreover, this study suggests that oxidative stress may be one of the mechanisms responsible for the worse outcome in hypothermic rats with cerulein-induced acute pancreatitis.BACKGROUND: Hipotermia é um evento freqüente em episódios de pancreatite aguda, contudo seu efeito real sobre pâncreas normal ainda não esta bem demonstrado. Além do mais, o efeito da hipotermia no decorrer da pancreatite aguda também não está completamente esclarecido. Uma das hipóteses sobre as causas das lesões causadas ou tratadas por hipotermia aventa a implicação de estresse oxidativo. OBJETIVOS: Investigar o efeito da hipotermia em ratos com pancreatite aguda induzida por ceruleína e o papel do estresse oxidativo neste processo. MÉTODOS: Ratos Wistar machos foram divididos em grupos hipotérmicos e normotérmicos. Hipotermia foi induzida com uma bolsa gelada de forma que a temperatura retal permanecesse em 30ºC por uma hora. Pancreatite aguda foi induzida com duas aplicações de ceruleína (20 ìg/kg) administradas com intervalo de uma hora. A amilase sérica, a permeabilidade vascular do pâncreas, a razão peso seco/peso úmido do pâncreas, a histopatologia e os níveis de glutationa foram analisados em cada grupo. RESULTADOS: Ratos hipotérmicos, com pancreatite aguda induzida por ceruleína, apresentaram maiores níveis de permeabilidade vascular no pâncreas (p < 0.05), razão peso seco/peso úmido do pâncreas (p = 0.03), e edema histológico (p < 0.05), mas os níveis de amilase sérica permaneceram iguais aos níveis apresentados pelos ratos normotérmicos. O grupo hipotérmico apresentou maior relação glutationa oxidada/glutationa reduzida em relação ao grupo normotérmico. CONCLUSÃO: Hipotermia moderada produziu uma maior resposta inflamatória em ratos com pancreatite aguda estabelecida, induzida por ceruleína, sugerindo que este efeito pode estar ligado a um maior índice de estresse oxidativo em ratos com pancreatite aguda

A pedagogic appraisal of the Priority Heuristic

We have explored how science and mathematics teachers made decisions when confronted with a dilemma in which a fictitious young woman, Deborah, may choose to have an operation that might address a painful spinal condition. We sought to explore the extent to which psychological heuristic models, in particular the Priority Heuristic, might successfully describe the decision-making process of these teachers and how an analysis of the role of personal and emotional factors in shaping the decision-making process might inform pedagogical design. A novel aspect of this study is that the setting in which the decision-making process is examined contrasts sharply with those used in psychological experiments. We found that to some extent, even in this contrasting setting, the Priority Heuristic could describe these teachers' decision-making. Further analysis of the transcripts yielded some insights into limitations on scope as well the richness and complexity in how personal factors were brought to bear. We see these limitations as design opportunities for educational intervention

El macrobentos y su relación con las fluctuaciones de salinidad en ríos y esteros del Chaco Oriental (Argentina)

In the area comprised between the Pilcomayo river (Formosa province) and the Amores river (Santa Fe province) 17 streams and rivers, and 4 swamps ("esteros") were studied in their lower reaches during low and high water periods. The salinity was high in some of them, specially during low water. Samples were taken with a Dietz-LaFond and modified Drzycimski dredges, according to the substrate characteristics, and filteres through a 500μm mesh size. Relative abundance and density (ind. m-2) were analized in relation with the main environmental factors, as current speed, conductivity, dissolved oxigen and sediment granulometry. The benthic macrofauna occurring in the streams and rivers showed important differences in their composition and density, being oligochaetes (Naididae and Tubificidae), chironomids (Chironominae) and molluscs (Hydrobiidae),&nbsp;the main groups.The swamp bottom fauna was rather poor, with abundance of oligochaetes, which could be due to the scarcity of dissolved oxygen and the high proportion of organic matter. The well oxigenated lotic environments, with moderate conductivity values, showed the richest and most abundant macrofauna, in contrast with those of high salinity, specially when the water level decreased. Conductivity was negatively correlated with the species number ( P &lt; 0,01) and abundance (P&lt; 0,01).In the area comprised between the Pilcomayo river (Formosa province) and the Amores river (Santa Fe province) 17 streams and rivers, and 4 swamps ("esteros") were studied in their lower reaches during low and high water periods. The salinity was high in some of them, specially during low water. Samples were taken with a Dietz-LaFond and modified Drzycimski dredges, according to the substrate characteristics, and filteres through a 500μm mesh size. Relative abundance and density (ind. m-2) were analized in relation with the main environmental factors, as current speed, conductivity, dissolved oxigen and sediment granulometry. The benthic macrofauna occurring in the streams and rivers showed important differences in their composition and density, being oligochaetes (Naididae and Tubificidae), chironomids (Chironominae) and molluscs (Hydrobiidae),&nbsp;the main groups.The swamp bottom fauna was rather poor, with abundance of oligochaetes, which could be due to the scarcity of dissolved oxygen and the high proportion of organic matter. The well oxigenated lotic environments, with moderate conductivity values, showed the richest and most abundant macrofauna, in contrast with those of high salinity, specially when the water level decreased. Conductivity was negatively correlated with the species number ( P &lt; 0,01) and abundance (P&lt; 0,01)

El Bentos del Parana Media en el tramo Corrientes-Esquina

Quali-quantitative variations of the benthos from the Middle Paraná river course, were studied. Spatial and temporal distribution was analyzed in relation with the main environmental factors. Studies were monthly carried out during March 1981-March 1982 in four stations near the localities of Comentes, Bella Vista, Coya and Esquina. In each of them, four sampling points were stablished in the cross sections of the river. Samples were obtained with a Dietz-LaFond dredge and fíltered through 500 and 150 µm mesh opening screens. The predominant sandy bottoms are inhabited by a specialized psammophilous fauna. The community structure was similar along all the studied stretch. Abundánce was very fluctuant, with maximun valúes of 160.000 ind/m2 with a strong numerical dominance of a species of Oligochaeta: Narapa bonettoi Correlations análysis showed a positive association between the mean grain size and the total abundance. These coeflcients were signiñcatives in all the stations for microturbellarians but only in Goya and Esquina for N. bonettoi Clay bank substraía from the river margins had a richer but less abundant fauna (maximun valúes of 29.000 ind/m2) with predominance of Xenochironomus sp. The benthos of the soft silty bottoms was the least diversé and abundant. Seasonal changes in the abundance were observed. There was an increment in spring and the early summer with a tendency to decrease during summer floods. This pattem was similar in the thxee kinds of bottoms, but more evident in the soft silty ones.Quali-quantitative variations of the benthos from the Middle Paraná river course, were studied. Spatial and temporal distribution was analyzed in relation with the main environmental factors. Studies were monthly carried out during March 1981-March 1982 in four stations near the localities of Comentes, Bella Vista, Coya and Esquina. In each of them, four sampling points were stablished in the cross sections of the river. Samples were obtained with a Dietz-LaFond dredge and fíltered through 500 and 150 µm mesh opening screens. The predominant sandy bottoms are inhabited by a specialized psammophilous fauna. The community structure was similar along all the studied stretch. Abundánce was very fluctuant, with maximun valúes of 160.000 ind/m2 with a strong numerical dominance of a species of Oligochaeta: Narapa bonettoi Correlations análysis showed a positive association between the mean grain size and the total abundance. These coeflcients were signiñcatives in all the stations for microturbellarians but only in Goya and Esquina for N. bonettoi Clay bank substraía from the river margins had a richer but less abundant fauna (maximun valúes of 29.000 ind/m2) with predominance of Xenochironomus sp. The benthos of the soft silty bottoms was the least diversé and abundant. Seasonal changes in the abundance were observed. There was an increment in spring and the early summer with a tendency to decrease during summer floods. This pattem was similar in the thxee kinds of bottoms, but more evident in the soft silty ones