Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human‐mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward‐time, agent‐based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a trade‐off between corridor quality and corridor design whereby populations connected by high‐quality habitat (i.e., low corridor mortality) are more resilient to suboptimal corridor design (e.g., long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long‐term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111750/1/eva12255.pd

The Millennium Galaxy Catalogue: the photometric accuracy, completeness and contamination of the 2dFGRS and SDSS-EDR/DR1 data sets

The Millennium Galaxy Catalogue (MGC) is a deep (μB,lim = 26 mag arcsec−2), wide-field, charge-coupled device imaging survey, covering 37.5 deg2. The MGC survey region is completely contained within the Two-Degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey Early Data Release (SDSS-EDR). We compare the photometry and completeness of the 2dFGRS and the SDSS-EDR with the MGC over the range 16 < B < 20 mag. We have also undertaken a photometric comparison to SuperCosmos (SCOS) and the Sloan Digital Sky Survey First Data Release (SDSS-DR1). We find that BMGC−B2dF = (0.035 ± 0.005) mag with an uncertainty of 0.142 mag per galaxy; BMGC−BSCOS = (0.032 ± 0.005) mag with an uncertainty of 0.108 mag; BMGC−BSDSS-EDR = (0.032 ± 0.005) mag with an uncertainty of 0.094 mag; and BMGC−BSDSS-DR1 = (0.039 ± 0.005) mag with an uncertainty of 0.086 mag. We find that high surface brightness 2dFGRS galaxies are systematically too faint, which leads to a significant scale error in magnitude. This effect is significantly reduced with the SCOS photometry. In the SDSS there is a weak non-linear scale error, which is negligible for faint galaxies. Low surface brightness galaxies in the SDSS are systematically fainter, consistent with the relative shallowness of this survey. We find that the 2dFGRS catalogue has (5.2 ± 0.3) per cent stellar contamination, (7.0 ± 0.4) per cent of objects resolved into two or more by the MGC, and is (8.7 ± 0.6) per cent incomplete compared to the MGC. From our all-object spectroscopic survey we find that the MGC is itself misclassifying (5.6 ± 1.3) per cent of galaxies as stars, and hence the 2dFGRS misses (14.3 ± 1.4) per cent of the galaxy population. The SDSS-EDR galaxy catalogue has (1.3 ± 0.1) per cent stellar contamination and (5.3 ± 1.0) per cent of galaxies misclassified as stars, with (0.18 ± 0.04) per cent of objects resolved into two or more by the MGC, and is (1.8 ± 0.1) per cent incomplete compared to the MGC. The total fraction of galaxies missing from the SDSS-EDR galaxy catalogue to BMGC = 20 mag, from incompleteness and misclassification, is (7.1 ± 1.0) per cen

Regulation of branching dynamics by axon-intrinsic asymmetries in Tyrosine Kinase Receptor signaling

Axonal branching allows a neuron to connect to several targets, increasing neuronal circuit complexity. While axonal branching is well described, the mechanisms that control it remain largely unknown. We find that in the Drosophila CNS branches develop through a process of excessive growth followed by pruning. In vivo high-resolution live imaging of developing brains as well as loss and gain of function experiments show that activation of Epidermal Growth Factor Receptor (EGFR) is necessary for branch dynamics and the final branching pattern. Live imaging also reveals that intrinsic asymmetry in EGFR localization regulates the balance between dynamic and static filopodia. Elimination of signaling asymmetry by either loss or gain of EGFR function results in reduced dynamics leading to excessive branch formation. In summary, we propose that the dynamic process of axon branch development is mediated by differential local distribution of signaling receptors

The Millennium Galaxy Catalogue: 16 < B_MGC < 24 galaxy counts and the calibration of the local galaxy luminosity function

The Millennium Galaxy Catalogue (MGC) is a 37.5 deg^2, medium-deep, B-band imaging survey along the celestial equator, taken with the Wide Field Camera on the Isaac Newton Telescope. The survey region is contained within the regions of both the Two Degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey Early Data Release (SDSS-EDR). The survey has a uniform isophotal detection limit of 26 mag arcsec^-2 and it provides a robust, well-defined catalogue of stars and galaxies in the range 16 <= B_MGC < 24 mag. Here we describe the survey strategy, the photometric and astrometric calibration, source detection and analysis, and present the galaxy number counts that connect the bright and faint galaxy populations within a single survey. We argue that these counts represent the state of the art and use them to constrain the normalizations (phi*) of a number of recent estimates of the local galaxy luminosity function. We find that the 2dFGRS, SDSS Commissioning Data (CD), ESO Slice Project, Century Survey, Durham/UKST, Mt Stromlo/APM, SSRS2, and NOG luminosity functions require a revision of their published phi* values by factors of 1.05 +/- 0.05, 0.76 +/- 0.10, 1.02 +/- 0.22, 1.02 +/- 0.16, 1.16 +/- 0.28, 1.75 +/- 0.37, 1.40 +/- 0.26 and 1.01 +/- 0.39, respectively. After renormalizing the galaxy luminosity functions we find a mean local \bj luminosity density of j_{b_J} = (1.986 +/- 0.031) x 10^8 h L_{\odot} Mpc^-3.Comment: 20 pages, LaTeX, 20 Postscript figures (some low resolution), MNRAS, in press; considerably revised versio

A semi-parametric approach to estimate risk functions associated with multi-dimensional exposure profiles: application to smoking and lung cancer

A common characteristic of environmental epidemiology is the multi-dimensional aspect of exposure patterns, frequently reduced to a cumulative exposure for simplicity of analysis. By adopting a flexible Bayesian clustering approach, we explore the risk function linking exposure history to disease. This approach is applied here to study the relationship between different smoking characteristics and lung cancer in the framework of a population based case control study

Early Fasting Is Long Lasting: Differences in Early Nutritional Conditions Reappear under Stressful Conditions in Adult Female Zebra Finches

Conditions experienced during early life can have profound effects on individual development and condition in adulthood. Differences in nutritional provisioning in birds during the first month of life can lead to differences in growth, reproductive success and survival. Yet, under natural conditions shorter periods of nutritional stress will be more prevalent. Individuals may respond differently, depending on the period of development during which nutritional stress was experienced. Such differences may surface specifically when poor environmental conditions challenge individuals again as adults. Here, we investigated long term consequences of differences in nutritional conditions experienced during different periods of early development by female zebra finches (Taeniopygia guttata) on measures of management and acquisition of body reserves. As nestlings or fledglings, subjects were raised under different nutritional conditions, a low or high quality diet. After subjects reached sexual maturity, we measured their sensitivity to periods of food restriction, their exploration and foraging behaviour as well as adult resting metabolic rate (RMR). During a short period of food restriction, subjects from the poor nutritional conditions had a higher body mass loss than those raised under qualitatively superior nutritional conditions. Moreover, subjects that were raised under poor nutritional conditions were faster to engage in exploratory and foraging behaviour. But RMR did not differ among treatments. These results reveal that early nutritional conditions affect adult exploratory behaviour, a representative personality trait, foraging and adult's physiological condition. As early nutritional conditions are reflected in adult phenotypic plasticity specifically when stressful situations reappear, the results suggest that costs for poor developmental conditions are paid when environmental conditions deteriorate

The statistics of natural hand movements.

Humans constantly use their hands to interact with the environment and they engage spontaneously in a wide variety of manual activities during everyday life. In contrast, laboratory-based studies of hand function have used a limited range of predefined tasks. The natural movements made by the hand during everyday life have thus received little attention. Here, we developed a portable recording device that can be worn by subjects to track movements of their right hand as they go about their daily routine outside of a laboratory setting. We analyse the kinematic data using various statistical methods. Principal component analysis of the joint angular velocities showed that the first two components were highly conserved across subjects, explained 60% of the variance and were qualitatively similar to those reported in previous studies of reach-to-grasp movements. To examine the independence of the digits, we developed a measure based on the degree to which the movements of each digit could be linearly predicted from the movements of the other four digits. Our independence measure was highly correlated with results from previous studies of the hand, including the estimated size of the digit representations in primary motor cortex and other laboratory measures of digit individuation. Specifically, the thumb was found to be the most independent of the digits and the index finger was the most independent of the fingers. These results support and extend laboratory-based studies of the human hand

Determining gene expression on a single pair of microarrays

<p>Abstract</p> <p>Background</p> <p>In microarray experiments the numbers of replicates are often limited due to factors such as cost, availability of sample or poor hybridization. There are currently few choices for the analysis of a pair of microarrays where N = 1 in each condition. In this paper, we demonstrate the effectiveness of a new algorithm called PINC (PINC is Not Cyber-T) that can analyze Affymetrix microarray experiments.</p> <p>Results</p> <p>PINC treats each pair of probes within a probeset as an independent measure of gene expression using the Bayesian framework of the Cyber-T algorithm and then assigns a corrected p-value for each gene comparison.</p> <p>The p-values generated by PINC accurately control False Discovery rate on Affymetrix control data sets, but are small enough that family-wise error rates (such as the Holm's step down method) can be used as a conservative alternative to false discovery rate with little loss of sensitivity on control data sets.</p> <p>Conclusion</p> <p>PINC outperforms previously published methods for determining differentially expressed genes when comparing Affymetrix microarrays with N = 1 in each condition. When applied to biological samples, PINC can be used to assess the degree of variability observed among biological replicates in addition to analyzing isolated pairs of microarrays.</p

Psychosocial impact of implantable cardioverter defibrillators (ICD) in young adults with Tetralogy of Fallot

Item does not contain fulltextOBJECTIVE: To investigate the psychosocial impact of having an implantable cardioverter defibrillator (ICD) in adults with Tetralogy of Fallot (ToF). METHODS: Included were 26 ToF-patients with an ICD (age 44 +/- 12 years), and two control groups consisting of 28 ToF-patients without an ICD (age 40 +/- 10 years) and a group of 35 ICD-patients of older age without ToF (age 72.0 +/- 8 years). This last control group was chosen to represent the "older general ICD population" with acquired heart disease seen at the out-patient clinic. Psychosocial functioning encompassed daily functioning, subjective health status, quality of life, anxiety, depression, coping and social support. RESULTS: ToF-patients with ICD showed diminished psychosocial functioning in comparison to ToF-patients without ICD. This was reflected by diminished subjectively perceived physical functioning (p = 0.01), general health perception (p < 0.01) and a lower satisfaction with life (p = 0.02). In comparison to older ICD-patients, ToF-patients with ICD showed less satisfaction with life (p = 0.03), experienced more anxiety (p = 0.01) and showed less favourable coping styles, although physical functioning was better for ToF-patients with ICD than for older ICD-patients (p = 0.01). More inappropriate shocks were found in ToF-patients with ICD compared to the older ICD-patients. CONCLUSION: In patients with ToF, ICD implantation had a major impact on psychosocial functioning which should be taken into account when considering ICD implantation in these young patients. To help improve psychosocial functioning, psychological counselling attuned to the specific needs of these patients may be useful.1 juli 201