A New Species of \u3ci\u3eHydrochara\u3c/i\u3e (Coleoptera: Hydrophilidae) from the Western Great Lakes Region

A new species Hydrochara simula (Coleoptera: Hydrophilidae) is described from Wis- consin and separated from other western Great Lakes species by a key. It is similar to H. obtusata (Say) and H. soror Smetana, but males can be easily recognized by a dorso-basal concavity of the aedeagus. Females can be distinguished from H. obtusata and H. soror by the more elongate penultimate segment of the maxillary palpus and other less consistent characters

Star cluster formation history along the minor axis of the Large Magellanic Cloud

We analysed Washington $CMT_1$ photometry of star clusters located along the minor axis of the LMC, from the LMC optical centre up to $\sim$ 39 degrees outwards to the North-West. The data base was exploited in order to search for new star cluster candidates, to produce cluster CMDs cleaned from field star contamination and to derive age estimates for a statistically complete cluster sample. We confirmed that 146 star cluster candidates are genuine physical systems, and concluded that an overall $\sim$ 30 per cent of catalogued clusters in the surveyed regions are unlikely to be true physical systems. We did not find any new cluster candidates in the outskirts of the LMC (deprojected distance $\ge$ 8 degrees). The derived ages of the studied clusters are in the range 7.2 < log($t$ yr$^{-1}$) $\le$ 9.4, with the sole exception of the globular cluster NGC\,1786 (log($t$ yr$^{-1}$) = 10.10). We also calculated the cluster frequency for each region, from which we confirmed previously proposed outside-in formation scenarios. In addition, we found that the outer LMC fields show a sudden episode of cluster formation (log($t$ yr$^{-1}$) $\sim$ 7.8-7.9) that continued until log($t$ yr$^{-1}$) $\sim$ 7.3 only in the outermost LMC region. We link these features to the first pericentre passage of the LMC to the MW, which could have triggered cluster formation due to ram pressure interaction between the LMC and MW halo.Comment: 13 pages, 4 figures. Accepted for publication in MNRA

A biomimetic basis for auditory processing and the perception of natural sounds

Biomimicry is a powerful science that aims to take advantage of nature's remarkable ability to devise innovative solutions to challenging problems. In the setting of hearing, mimicking how humans hear is the foremost strategy in designing effective artificial hearing approaches. In this work, we explore the mathematical foundations for the exchange of design inspiration and features between biological hearing systems, artificial sound-filtering devices, and signal processing algorithms. Our starting point is a concise asymptotic analysis of subwavelength acoustic metamaterials. We are able to fine tune this structure to mimic the biomechanical properties of the cochlea, at the same scale. We then turn our attention to developing a biomimetic signal processing algorithm. We use the response of the cochlea-like structure as an initial filtering layer and then add additional biomimetic processing stages, designed to mimic the human auditory system's ability to recognise the global properties of natural sounds

On the effects of self- and cross-phase modulation on photon purity for four-wave mixing photon-pair sources

We consider the effect of self-phase modulation and cross-phase modulation on the joint spectral amplitude of photon pairs generated by spontaneous four-wave mixing. In particular, the purity of a heralded photon from a pair is considered, in the context of schemes that aim to maximise the purity and minimise correlation in the joint spectral amplitude using birefringent phase-matching and short pump pulses. We find that non-linear phase modulation effects will be detrimental, and will limit the quantum interference visibility that can be achieved at a given generation rate. An approximate expression for the joint spectral amplitude with phase modulation is found by considering the group velocity walk-off between each photon and the pump, but neglecting the group-velocity dispersion at each wavelength. The group-velocity dispersion can also be included with a numerical calculation, and it is shown that it only has a small effect on the purity for the realistic parameters considered.Comment: 11 pages, 10 figure

Campus-Based Agriculture: The Future of Food at Gettysburg College

This research investigates various methods for producing food on the campus of Gettysburg College in order to improve food sustainability. The transportation of food contributes to the increased use of fossil fuels, which in turn leads to global warming and climate change. By producing a larger portion of its food on-campus, Gettysburg College could reduce the amount of food transported to the school, thereby lessening the College’s environmental impact. Urban farming techniques, hydroponics, aquaponics, and greenhouse-based agriculture are explored as viable methods for achieving this goal. Examples of the use of these techniques on college campuses are drawn from Allegheny College, Acadia University, and Cornell University, among others. Possible strategies for Gettysburg College’s implementation of the farming techniques proposed in this research are also included throughout

PXR-mediated Metabolism During Pregnancy and Cholestasis

Nuclear receptors, including the pregnane x receptor (PXR) and the farnesoid x receptor (FXR), regulate the expression of genes that maintain bile acid (BA) homeostasis. Intrahepatic cholestasis of pregnancy (ICP) is a common gestational liver disease and BAs are implicated in its pathogenesis. Rodents exhibit maternal liver growth in order to meet the metabolic demands of pregnancy. This process is found to precede changes in body weight, occur in the presence of raised serum BAs and is likely to be driven by a placental lactogen. While the growth is normally achieved by hepatocyte hypertrophy, potentially harmful hyperplasia makes a major contribution in mice lacking Fxr. Consistent with reports of raised serum BAs in normal pregnant women, hepatic BAs are found in association with pro-cholestatic gene expression in normal pregnant mice. Gestation could be a state of reduced Fxr function because BA-fed and Fxr-/- mice do not develop raised hepatic BAs during pregnancy. Sequencing and functional assessment of PXR variants revealed that polymorphisms in this gene are unlikely to contribute to the aetiology of ICP. Surprisingly, Pxr-/- mice have enhanced hepatic metabolism and are resistant to toxicity caused by lithocholic acid (LCA). Furthermore, while hepatic Pxr is activated by intraperitoneal injection of LCA, it is not activated by physiologically relevant LCA-feeding. Summary: Pregnancy causes liver growth, raised hepatic BA and pro-cholestatic gene expression in normal mice. In humans, these adaptations may expose predisposed individuals to gestational liver disease. Genetic variation in PXR does not contribute to ICP and Pxr may play only a limited role in mediating hepatic responses to toxic BAs

Pass the port(o) to the right - building a community of practice for Portuguese professors to profess

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