Shearwater Foraging in the Southern Ocean: The Roles of Prey Availability and Winds

Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. Conclusions/Significance The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem

DNA-based faecal dietary analysis: A comparison of qPCR and high throughput sequencing approaches

The genetic analysis of faecal material represents a relatively non-invasive way to study animal diet and has been widely adopted in ecological research. Due to the heterogeneous nature of faecal material the primary obstacle, common to all genetic approaches, is a means to dissect the constituent DNA sequences. Traditionally, bacterial cloning of PCR amplified products was employed; less common has been the use of species-specific quantitative PCR (qPCR) assays. Currently, with the advent of High-Throughput Sequencing (HTS) technologies and indexed primers it has become possible to conduct genetic audits of faecal material to a much greater depth than previously possible. To date, no studies have systematically compared the estimates obtained by HTS with that of qPCR. What are the relative strengths and weaknesses of each technique and how quantitative are deep-sequencing approaches that employ universal primers? Using the locally threatened Little Penguin (Eudyptula minor) as a model organism, it is shown here that both qPCR and HTS techniques are highly correlated and produce strikingly similar quantitative estimates of fish DNA in faecal material, with no statistical difference. By designing four species-specific fish qPCR assays and comparing the data to the same four fish in the HTS data it was possible to directly compare the strengths and weaknesses of both techniques. To obtain reproducible quantitative data one of the key, and often overlooked, steps common to both approaches is ensuring that efficient DNA isolation methods are employed and that extracts are free of inhibitors. Taken together, the methodology chosen for long-term faecal monitoring programs is largely dependent on the complexity of the prey species present and the level of accuracy that is desired. Importantly, these methods should not be thought of as mutually exclusive, as the use of both HTS and qPCR in tandem will generate datasets with the highest fidelity

The effect of different ambient temperatures on local sympathetic activity in rats

İki grup halinde yapılan deneylerde (5 ve 16 - saat) Wistar-Albino sıçanlar (200-260 gr) 5°C, 20°C, 36°C ve 42°C lerde tutularak idrarlarındaki katekolamin miktarı saptandı. Katekolamin yöntem tayini, idrardaki katekolaminleri uygun PH da alüminyum okside bağlamak ve sonra geri alarak okside edip, oksidasyon sırasında açığa çıkan fluoresans şiddetini spectrafotofluorometre'de ölçmek esasına dayanmaktadır. Bulgularımızda 5 saat 42°C lik ortamda tutulan sıçanların idrar miktarları, kontrol grubu olarak çalıştığımız 20°C lik ortamda tutulan sıçanların katekolamin miktarlarından yüksek bulundu. Aynı koşullarda 16 saat 5°C ve 42°C de tutulan sıçanların idrarlarındaki katekolamin miktarında da benzer oranda artış görüldü. Sarnıç olarak ısının, sıçanlarda sempatik sistemi, etkileyerek strese yol açtığı ve stresin de katekolamin miktarını arttırdığı düşünüldü

Subcellular localization and functional expression of the glycerol uptake protein 1 (GUP1) of Saccharomyces cerevisiae tagged with green fluorescent protein

GFP (green fluorescent protein) from Aequorea victoria was used as an in vivo reporter protein when fused to the N- and C-termini of the glycerol uptake protein 1 (Gup1p) of Saccharomyces cerevisiae. The subcellular localization and functional expression of biologically active Gup1–GFP chimaeras was monitored by confocal laser scanning and electron microscopy, thus supplying the first study of GUP1 dynamics in live yeast cells. The Gup1p tagged with GFP is a functional glycerol transporter localized at the plasma membrane and endoplasmic reticulum levels of induced cells. The factors involved in proper localization and turnover of Gup1p were revealed by expression of the Gup1p–GFP fusion protein in a set of strains bearing mutations in specific steps of the secretory and endocytic pathways. The chimaerical protein was targeted to the plasma membrane through a Sec6-dependent process; on treatment with glucose, it was endocytosed through END3 and targeted for degradation in the vacuole. Gup1p belongs to the list of yeast proteins rapidly down-regulated by changing the carbon source in the culture medium, in agreement with the concept that post-translational modifications triggered by glucose affect proteins of peripheral functions. The immunoelectron microscopy assays of cells expressing either Gup1–GFP or GFP–Gup1 fusions suggested the Gup1p membrane topology: the N-terminus lies in the periplasmic space, whereas its C-terminal tail has an intracellular location. An extra cytosolic location of the N-terminal tail is not generally predicted or determined in yeast membrane transporters

Depressive symptomatology and fall risk among community-dwelling older adults

RationaleFalls are common among older adults and may be related to depressive symptoms (DS). With advancing age, there is an onset of chronic conditions, sensory impairments, and activity limitations that are associated with falls and with depressive disorders. Prior cross-sectional studies have observed significant associations between DS and subsequent falls as well as between fractures and subsequent clinical depression and DS.ObjectiveThe directionality of these observed relationship between falls and DS is in need of elaboration given that cross-sectional study designs can yield biased estimates of the DS-falls relationship.MethodsUsing 2006-2010 Health and Retirement Study data, cross-lagged panel structural equation models were used to evaluate associations between falls and DS among 7233 community-dwelling adults ages ≥65. Structural coefficients between falls and DS (in 2006→2008, 2008→2010) were estimated.ResultsA good-fitting model was found: Controlling for baseline (2006) physical functioning, vision, chronic conditions, and social support and neighborhood social cohesion, falls were not associated with subsequent DS, but a 0.5 standard deviation increase in 2006 DS was associated with a 30% increase in fall risk two years later. This DS-falls relationship was no longer significant when use of psychiatric medications, which was positively associated with falls, was included in the model.ConclusionUsing sophisticated methods and a large U.S. sample, we found larger magnitudes of effect in the DS-falls relationship than in prior studies-highlighting the risk of falls for older adults with DS. Medical providers might assess older individuals for DS as well as use of psychotropic medications as part of a broadened falls prevention approach. National guidelines for fall risk assessments as well as quality indicators for fall prevention should include assessment for clinical depression