Assessing the food preference of the brushtail possum (Trichosurus vulpecular) using fixed-ratio schedules

The quality of different foods has been found in previous studies to effect an animal’s performance on fixed-ratio schedules. Foods that are of a higher quality should maintain behaviour to larger fixed-ratio values than foods of a lower quality. The present study examined the performance maintained by increasing fixed-ratio schedules by four different foods (Rolled Oats, Cocoa Puffs™ and flaked barley, All Bran™ and Soy Protein) with six brushtail possum (Trischosurus vulpecula). Overall response rates and running response rates both generally showed a bitonic function, and post-reinforcement pauses showed a modest increase with increases in the fixed-ratio. The equations of two quantitative models; Behavioural economics and mathematical principles of reinforcement (MPR) were fitted to the data to see how different food types affected the two models ability to predict behaviour. This was measured through two parameter estimates, alpha (α) and specific activation (αs). Both demand equations and the MPR equation described the data fairly well. The parameter estimates for specific activation (αs) showed a significant difference in value across the foods, but there was no significant difference across foods for parameter estimates of alpha (α). There was a weak correlation between parameter estimates of α and αs (r =-0.245, p =0.0926) . The four foods used in this study were also tested in a paired-stimulus preference assessment. The foods that were assessed as being of more value in the behavioural economic equations and the MPR model, for some possums were identified as being more preferred, but this was not consistent for all possums

The Genetic Basis of the Polycystic Ovary Syndrome: A Literature Review Including Discussion of PPAR-γ

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of the women of reproductive age. Familial clustering of PCOS has been consistently reported suggesting that genetic factors play a role in the development of the syndrome although PCOS cases do not exhibit a clear pattern of Mendelian inheritance. It is now well established that PCOS represents a complex trait similar to type-2 diabetes and obesity, and that both inherited and environmental factors contribute to the PCOS pathogenesis. A large number of functional candidate genes have been tested for association or linkage with PCOS phenotypes with more negative than positive findings. Lack of universally accepted diagnostic criteria, difficulties in the assignment of male phenotype, obscurity in the mode of inheritance, and particularly small sample size of the study populations appear to be major limitations for the genetic studies of PCOS. In the near future, utilizing the genome-wide scan approach and the HapMap project will provide a stronger potential for the genetic analysis of the syndrome

Cognitive effects of the progressive exercise test in electricians wearing personal protective equipment.

Objetivo: verificar o efeito do esfor?o f?sico sobre as fun??es cognitivas de trabalhadores eletricistas utilizando equipamento de prote??o individual (EPI). M?todos: participaram 28 eletricistas que trabalhavam na constru??o, manuten??o e opera??o de redes de distribui??o de energia. Todos do sexo masculino, sadios e aptos para a pr?tica de exerc?cios f?sicos. As fun??es cognitivas foram representadas pelo teste de rea??o simples (TRS) e pelo n?vel de vigil?ncia mental (NVM). O TRS e o NVM foram mensurados pr? e p?s- -teste m?ximo progressivo, em esteira rolante, a 27 ?C de temperatura seca e umidade relativa do ar de 64%. O teste consistiu em aumentos progressivos na velocidade e na inclina??o da esteira at? a fadiga, com utiliza??o de EPI. Resultados: a m?dia (desvio padr?o) do TRS n?o foi significativamente diferente antes, 227,8 (35,1) ms, e ap?s o exerc?cio, 220,6 (24,6) ms. O NVM foi significativamente maior ap?s o exerc?cio em todas as situa??es: frequ?ncia crescente ? 36,5 (5,1) Hz vs 39,5 (2,7) Hz, frequ?ncia decrescente ? 36,0 (5,2) vs 39,0 (3,88) Hz, e frequ?ncia geral ? 36,2 (4,9) vs 39,2 (3,1) Hz. Conclus?o: o exerc?cio progressivo m?ximo realizado com EPI n?o modificou o tempo de rea??o simples e aumentou o n?vel de vigil?ncia mental de eletricistas.Objective: to verify the effects of physical effort on the cognitive functions of electricians wearing personal protective equipment (PPE). Methods: 28 electricians participated. They worked on the construction, maintenance and operation of electrical power distribution networks. All were male, healthy and able to practice physical exercises. The cognitive functions were checked by measuring simple reaction time (SRT) and mental alertness level (MAL). SRT and MAL were measured before and after progressive maximal exercise, on a treadmill, at 27 ?C dry temperature and 64% relative humidity, wearing PPE. The test consisted of progressive increases in treadmill speed and incline, until fatigue. Results: SRT mean difference was not significantly different before ? 227.8 (35.1) ms ? and after exercising ?220.6 (24.6) ms. MAL was significantly higher after exercise in all situations: increasing frequency - 36.5 (5.1) Hz vs. 39.5 (2.7) Hz; decreasing frequency-36.0 (5.2) Hz vs. 39.0 (3.88) Hz; and general frequency 36.2 (4.9) Hz vs. 39.2 (3.1) Hz. Conclusion: progressive maximal exercise performed while wearing PPE caused no change in simple reaction time, and increased electricians? mental alertness level

Prenylated flavonoid-enriched fraction from maclura tinctoria shows biological activity against Staphylococcus aureus and protects galleria mellonella larvae from bacterial infection.

Background: The Atlantic Forest biome extends along the entire Brazilian coast and is home to approximately 20,000 plant species, many of which are endemic; it is considered one of the hotspot regions of the planet. Several of these species are sources of natural products with biological activities that are still unknown. In this study, we evaluated the antimicrobial activity of 90 extracts derived from native Atlantic Forest tree species against Staphylococcus aureus, an important human and veterinary pathogen. Methods: Extracts from native Atlantic Forest tree species were evaluated for their antimicrobial activity against S. aureus by in vitro standard methods. Phytochemical fractionation of the extract from Maclura tinctoria was performed by liquid-liquid partitioning. LC-DAD-ESI-MS was used for identification of constituents in the most active fraction. Damage of cells and alterations in the permeability of cell membrane were determined by atomic force microscopy (AFM) and crystal violet uptake assay, respectively. In vivo antimicrobial activity was evaluated using Galleria mellonella larvae infected with S. aureus with survival data collected using the Kaplan-Meier method. Results: Among the organic or aqueous extracts tested here, 26 showed biological activity. Eight species showed relevant results, with a minimum inhibitory concentration (MIC) below 1?mg/mL. Antibacterial activity was registered for three species for the first time. An organic extract from Maclura tinctoria leaves showed the lowest MIC (0.08?mg/mL). Fractionation of this extract by liquid-liquid partitioning led to obtaining fraction 11FO d with a MIC of 0.04?mg/mL. This fraction showed strong activity against veterinary S. aureus isolates and contributed to the increased survival of Galleria mellonella larvae infected with S. aureus ATCC 29213. The bacterial surface was not altered by the presence of 11FO d, and no cell membrane damage was detected. The LC-DAD-ESI/MS analyses identified prenylated flavonoids as the major constituents responsible for the antibacterial activity of this active extract. Conclusion: A fraction enriched in prenylated isoflavones and flavanones from M. tinctoria showed in vitro and in vivo efficacy as antistaphylococcal agents. These findings justify the need for further research to elucidate the mechanisms of action of these compounds

Neural responses in parietal and occipital areas in response to visual events are modulated by prior multisensory stimuli

The effect of multi-modal vs uni-modal prior stimuli on the subsequent processing of a simple flash stimulus was studied in the context of the audio-visual 'flash-beep' illusion, in which the number of flashes a person sees is influenced by accompanying beep stimuli. EEG recordings were made while combinations of simple visual and audio-visual stimuli were presented. The experiments found that the electric field strength related to a flash stimulus was stronger when it was preceded by a multi-modal flash/beep stimulus, compared to when it was preceded by another uni-modal flash stimulus. This difference was found to be significant in two distinct timeframes--an early timeframe, from 130-160 ms, and a late timeframe, from 300-320 ms. Source localisation analysis found that the increased activity in the early interval was localised to an area centred on the inferior and superior parietal lobes, whereas the later increase was associated with stronger activity in an area centred on primary and secondary visual cortex, in the occipital lobe. The results suggest that processing of a visual stimulus can be affected by the presence of an immediately prior multisensory event. Relatively long-lasting interactions generated by the initial auditory and visual stimuli altered the processing of a subsequent visual stimulus.status: publishe

Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body

Supereruptions violently transfer huge amounts (100 s–1000 s km3) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted ∼760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500–3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies

Impact of nonoptimal intakes of saturated, polyunsaturated, and trans fat on global burdens of coronary heart disease

Background: Saturated fat (SFA), ω‐6 (n‐6) polyunsaturated fat (PUFA), and trans fat (TFA) influence risk of coronary heart disease (CHD), but attributable CHD mortalities by country, age, sex, and time are unclear. Methods and Results: National intakes of SFA, n‐6 PUFA, and TFA were estimated using a Bayesian hierarchical model based on country‐specific dietary surveys; food availability data; and, for TFA, industry reports on fats/oils and packaged foods. Etiologic effects of dietary fats on CHD mortality were derived from meta‐analyses of prospective cohorts and CHD mortality rates from the 2010 Global Burden of Diseases study. Absolute and proportional attributable CHD mortality were computed using a comparative risk assessment framework. In 2010, nonoptimal intakes of n‐6 PUFA, SFA, and TFA were estimated to result in 711 800 (95% uncertainty interval [UI] 680 700–745 000), 250 900 (95% UI 236 900–265 800), and 537 200 (95% UI 517 600–557 000) CHD deaths per year worldwide, accounting for 10.3% (95% UI 9.9%–10.6%), 3.6%, (95% UI 3.5%–3.6%) and 7.7% (95% UI 7.6%–7.9%) of global CHD mortality. Tropical oil–consuming countries were estimated to have the highest proportional n‐6 PUFA– and SFA‐attributable CHD mortality, whereas Egypt, Pakistan, and Canada were estimated to have the highest proportional TFA‐attributable CHD mortality. From 1990 to 2010 globally, the estimated proportional CHD mortality decreased by 9% for insufficient n‐6 PUFA and by 21% for higher SFA, whereas it increased by 4% for higher TFA, with the latter driven by increases in low‐ and middle‐income countries. Conclusions: Nonoptimal intakes of n‐6 PUFA, TFA, and SFA each contribute to significant estimated CHD mortality, with important heterogeneity across countries that informs nation‐specific clinical, public health, and policy priorities.peer-reviewe