Numerical Response of Breeding Birds Following Experimental Selection Harvesting in Northern Hardwood Forests

Silvicultural treatments have been shown to alter the composition of species assemblages in numerous taxa. However, the intensity and persistence of these effects have rarely been documented. We used a before-after, control-impact (BACI) paired design, i.e., five pairs of 25-ha study plots, 1-control and 1-treated plot, to quantify changes in the density of eight forest bird species in response to selection harvesting over six breeding seasons, one year pre- and five years postharvest. Focal species included mature forest associates, i.e., Northern Parula (Setophaga americana) and Black-throated Green Warbler (Setophaga virens), forest generalists, i.e., Yellow-bellied Sapsucker (Sphyrapicus varius) and Swainson’s Thrush (Catharus ustulatus), early-seral specialists, i.e., Mourning Warbler (Geothlypis philadelphia) and Chestnut-sided Warbler (Setophaga pensylvanica), species associated with shrubby forest gaps, i.e., Black-throated Blue Warbler (Setophaga caerulescens), and mid-seral species, i.e., American Redstart (Setophaga ruticilla). As predicted, we found a negative numerical response to the treatment in the Black-throated Green Warbler, no treatment effect in the Yellow-bellied Sapsucker, and a positive treatment effect in early-seral specialists. We only detected a year effect in the Northern Parula and the American Redstart. There was evidence for a positive treatment effect on the Swainson’s Thrush when the regeneration started to reach the pole stage, i.e., fifth year postharvest. These findings suggest that selection harvesting has the potential to maintain diverse avian assemblages while allowing sustainable management of timber supply, but future studies should determine whether mature-forest associates can sustain second- and third-entry selection harvest treatments.

Predicting microbial pollution concentrations in UK rivers in response to land use change

The Water Framework Directive has caused a paradigm shift towards the integrated management of recreational water quality through the development of drainage basin-wide programmes of measures. This has increased the need for a cost-effective diagnostic tool capable of accurately predicting riverine faecal indicator organism (FIO) concentrations. This paper outlines the application of models developed to fulfil this need, which represent the first transferrable generic FIO models to be developed for the UK to incorporate direct measures of key FIO sources (namely human and livestock population data) as predictor variables. We apply a recently developed transfer methodology, which enables the quantification of geometric mean presumptive faecal coliforms and presumptive intestinal enterococci concentrations for base- and high-flow during the summer bathing season in unmonitored UK watercourses, to predict FIO concentrations in the Humber river basin district. Because the FIO models incorporate explanatory variables which allow the effects of policy measures which influence livestock stocking rates to be assessed, we carry out empirical analysis of the differential effects of seven land use management and policy instruments (fiscal constraint, production constraint, cost intervention, area intervention, demand-side constraint, input constraint, and micro-level land use management) all of which can be used to reduce riverine FIO concentrations. This research provides insights into FIO source apportionment, explores a selection of pollution remediation strategies and the spatial differentiation of land use policies which could be implemented to deliver river quality improvements. All of the policy tools we model reduce FIO concentrations in rivers but our research suggests that the installation of streamside fencing in intensive milk producing areas may be the single most effective land management strategy to reduce riverine microbial pollution.

Recruitment of the infaunal bivalve Soletellina Alba (Lamark,1818) (Bivalvia: Psammobiidae) in response to different sediment types and water depths within the intermittently open Hopkins River estuary

Studies examining recruitment processes for soft-sediment macroinvertebrate fauna in intermittent estuaries are rare and most studies of active habitat selection have been tested in the laboratory rather than the field. The present field study examined whether recruitment of the infaunal bivalve Soletellina alba was influenced by water depth and sediment particle size in the intermittent Hopkins River estuary, southern Australia. The number of recruits in sediment trays differed between water depths, but active habitat selection was not evident across treatments of varying sediment particle size. The use of sediments with varying particle sizes also provided an opportunity to identify potential discontinuities in body-size distributions of recruits associated with varying habitat architecture. The length (mm) of recruits was converted to the same scale used to express sediment particle size (i.e. phi units: phi = − log2 of sediment particle size). The size of recruits differed across water depths, but did not differ across treatments with fine (phi = 3) versus coarse (phi = 1) sediment, and no relationships were apparent between bivalve size and sediments consisting of varying particle size. These patterns of recruitment do not correspond with the distribution of adult S. alba within the Hopkins River estuary. Previous sampling has shown that abundances of juvenile and adult S. alba are variable across time, site and water depth, but are often greater at the deeper water depth (1.05 m below the Australian Height Datum). However, recruitment during the present study was greatest at the shallower water depth (0.05 m below AHD), and the apparent absence of active habitat selection suggests that the distribution of adults is unlikely to be attributable to differences in recruitment associated with sediments of varying particle size.

Heterologous microarray experiments used to identify the early gene response to heat stress in a coral reef fish

Coral reef fishes are expected to experience rising sea surface temperatures due to climate change. How well tropical reef fishes will respond to these increased temperatures and which genes are important in the response to elevated temperatures is not known. Microarray technology provides a powerful tool for gene discovery studies, but the development of microarrays for individual species can be expensive and time-consuming. In this study, we tested the suitability of a Danio rerio oligonucleotide microarray for application in a species with few genomic resources, the coral reef fish Pomacentrus moluccensis. Results from a comparative genomic hybridization experiment and direct sequence comparisons indicate that for most genes there is considerable sequence similarity between the two species, suggesting that the D. rerio array is useful for genomic studies of P. moluccensis. We employed this heterologous microarray approach to characterize the early transcriptional response to heat stress in P. moluccensis. A total of 111 gene loci, many of which are involved in protein processing, transcription, and cell growth, showed significant changes in transcript abundance following exposure to elevated temperatures. Changes in transcript abundance were validated for a selection of candidate genes using quantitative real-time polymerase chain reaction. This study demonstrates that heterologous microarrays can be successfully employed to study species for which specific microarrays have not yet been developed, and so have the potential to greatly enhance the utility of microarray technology to the field of environmental and functional genomics.

Spatial ability is impaired and mineralcorticoid receptor mRNA expression in zebra finches (Taeniopygia guttata) selected for acute high corticosterone response to stress

In mammals, stress hormones have profound influences on spatial learning and memory. Here, we investigated whether glucocorticoids influence cognitive abilities in birds by testing a line of zebra finches selectively bred to respond to an acute stressor with high plasma corticosterone (CORT) levels. Cognitive performance was assessed by spatial and visual one-trial associative memory tasks. Task performance in the high CORT birds was compared with that of the random-bred birds from a control breeding line. The birds selected for high CORT in response to an acute stressor performed less well than the controls in the spatial task, but there were no significant differences between the lines in performance during the visual task. The birds from the two lines did not differ in their plasma CORT levels immediately after the performance of the memory tasks; nevertheless, there were significant differences in peak plasma CORT between the lines. The high CORT birds also had significantly lower mineralocorticoid receptor mRNA expression in the hippocampus than the control birds. There was no measurable difference between the lines in glucocorticoid receptor mRNA density in either the hippocampus or the paraventricular nucleus. Together, these findings provide evidence to suggest that stress hormones have important regulatory roles in avian spatial cognition.

Sex-specific developmental plasticity in response to yolk corticosterone in an oviparous lizard

Corticosterone exposure during prenatal development as a result of maternal upregulation of circulating hormone levels has been shown to have effects on offspring development in mammals. Corticosterone has also been documented in egg yolk in oviparous vertebrates, but the extent to which this influences phenotypic development is less studied. We show that maternal corticosterone is transferred to egg yolk in an oviparous lizard (the mallee dragon, Ctenophorus fordi Storr), with significant variation among clutches in hormone levels. Experimental elevation of yolk corticosterone did not affect hatching success, incubation period or offspring sex ratio. However, corticosterone did have a sex-specific effect on skeletal growth during embryonic development. Male embryos exposed to relatively high levels of corticosterone were smaller on average than control males at hatching whereas females from hormone-treated eggs were larger on average than control females. The data thus suggest that males are not just more sensitive to the detrimental effects of corticosterone but rather that the sexes may have opposite responses to corticosterone during development. Positive selection on body size at hatching for both sexes in this species further suggests that increased corticosterone in egg yolk may have sex-specific fitness consequences, with potential implications for sex allocation and the evolution of hormone-mediated maternal effects.

Sex-biased space-use response to urbanization in an endemic urban adapter

Urbanization impacts on the composition and distribution of wildlife. The tawny frogmouth (Podargus strigoides) is an endemic, nocturnal bird species widespread throughout Australia with recent research highlighting high densities within urban environments. The aim of this study was to investigate homerange size and land-use in response to a gradient of urbanization by determining (a) the key land-use types influencing home-range size and location in the urban landscape (b) whether urbanization impacts on home-range size; and (c) whether the response to urbanization is gender specific. Twelve birds, seven male and five female were radio-tracked within a study zone located in Melbourne, Australia. We used minimum convex polygons (MCP) 95% and 50% fixed-kernel isopleths to calculate home-range size and areas of core use within each home-range. In both the landscape and core areas of their home-range, birds positioned their home-range in areas with more trees, avoiding impervious surfaces and utilizing grassed areas. Male mean kernel home-range was 17.65 ± 4.35 ha and female 6.55 ± 1.40 ha. Male home-ranges contained higher levels of impervious surfaces than females. Modelling demonstrated that as urbanization intensified the home-range size of males increased whereas female home-ranges remained static in size. This research identifies land-use selection and highlights the possibility that spatial behaviour in the species is sex-biased in response to a gradient of urbanization. © 2014 Elsevier B.V.

Growth of populations and the fungus garden of Atta sexdens rubropilosa (Hymenoptera, Formicidae) response to foraged substrates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of tissue response to periodontal dressings: Histological study in tooth sockets of rats

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p < 0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p < 0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p < 0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pac (TM) dressing induced a more intensive inflammatory reaction at 28 days.

How individual movement response to habitat edges affects population persistence and spatial spread

How individual-level movement decisions in response to habitat edges influence population-level patterns of persistence and spread of a species is a major challenge in spatial ecology and conservation biology. Here, we integrate novel insights into edge behavior, based on habitat preference and movement rates, into spatially explicit growth-dispersal models. We demonstrate how crucial ecological quantities (e.g., minimal patch size, spread rate) depend critically on these individual-level decisions. In particular, we find that including edge behavior properly in these models gives qualitatively different and intuitively more reasonable results than those of some previous studies that did not consider this level of detail. Our results highlight the importance of new empirical work on individual movement response to habitat edges. © 2013 by The University of Chicago.

Relationships between physiological traits and productivity of sugarcane in response to water deficit

The relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (F (v)/F (m)), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with F (v)/F (m), SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.

Optimal Timing for Assessment of Tumor Response to Neoadjuvant Chemoradiation in Patients With Rectal Cancer: Do All Patients Benefit From Waiting Longer Than 6 Weeks?

Purpose: To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-D-glucose-labeled positron emission tomography/computed tomography ([18 FDG] PET/CT) imaging and correlate with response to CRT. Methods and Materials: Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials. org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks fromCRT completion). Clinical assessment was at 12 weeks. Maximal standard uptakevalue (SUVmax) of the primary tumor wasmeasured and recorded at eachPET/CTstudy after 1 h (early) and3 h (late) from 18 FDGinjection. Patientswith an increase in early SUVmax between 6 and 12 weeks were considered " bad" responders and the others as "good" responders. Results: Ninety-one patients were included; 46 patients (51%) were "bad" responders, whereas 45 (49%) patients were " good" responders. " Bad" responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; PZ. 001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; PZ. 008) and exhibited greater final tumor dimension (4.3cmvs. 3.3cm; PZ. 03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CTwas a significant predictor of " good" response (accuracy of 67%). Conclusions: Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients. (C) 2012 Elsevier Inc.

Cardiovascular response to beta-adrenergic blockade or activation in 23 inbred mouse strains

We report the characterisation of 27 cardiovascular-related traits in 23 inbred mouse strains. Mice were phenotyped either in response to chronic administration of a single dose of the beta-adrenergic receptor blocker atenolol or under a low and a high dose of the beta-agonist isoproterenol and compared to baseline condition. The robustness of our data is supported by high trait heritabilities (typically H(2)>0.7) and significant correlations of trait values measured in baseline condition with independent multistrain datasets of the Mouse Phenome Database. We then focused on the drug-, dose-, and strain-specific responses to beta-stimulation and beta-blockade of a selection of traits including heart rate, systolic blood pressure, cardiac weight indices, ECG parameters and body weight. Because of the wealth of data accumulated, we applied integrative analyses such as comprehensive bi-clustering to investigate the structure of the response across the different phenotypes, strains and experimental conditions. Information extracted from these analyses is discussed in terms of novelty and biological implications. For example, we observe that traits related to ventricular weight in most strains respond only to the high dose of isoproterenol, while heart rate and atrial weight are already affected by the low dose. Finally, we observe little concordance between strain similarity based on the phenotypes and genotypic relatedness computed from genomic SNP profiles. This indicates that cardiovascular phenotypes are unlikely to segregate according to global phylogeny, but rather be governed by smaller, local differences in the genetic architecture of the various strains.

Does clutch size evolve in response to parasites and immunocompetence?

Parasites have been argued to influence clutch size evolution, but past work and theory has largely focused on within-species optimization solutions rather than clearly addressing among-species variation. The effects of parasites on clutch size variation among species can be complex, however, because different parasites can induce age-specific differences in mortality that can cause clutch size to evolve in different directions. We provide a conceptual argument that differences in immunocompetence among species should integrate differences in overall levels of parasite-induced mortality to which a species is exposed. We test this assumption and show that mortality caused by parasites is positively correlated with immunocompetence measured by cell-mediated measures. Under life history theory, clutch size should increase with increased adult mortality and decrease with increased juvenile mortality. Using immunocompetence as a general assay of parasite-induced mortality, we tested these predictions by using data for 25 species. We found that clutch size increased strongly with adult immunocompetence. In contrast, clutch size decreased weakly with increased juvenile immunocompetence. But, immunocompetence of juveniles may be constrained by selection on adults, and, when we controlled for adult immunocompetence, clutch size decreased with juvenile immunocompetence. Thus, immunocompetence seems to reflect evolutionary differences in parasite virulence experienced by species, and differences in age-specific parasite virulence appears to exert opposite selection on clutch size evolution.

Pathogenic autoantibodies are routinely generated during the response to foreign antigen: a paradigm for autoimmune disease.

The immune system's ability to distinguish self and nonself is essential for both host defense against foreign agents and protection of self-antigens from autoimmune destruction. Such discrimination is complicated by extensive structural homology shared between foreign and self antigens. One hypothesis to explain the development of an autoimmune response is that some B cells activated by foreign antigen acquire, through somatic mutation, specificity for both the eliciting foreign antigen and self antigen. If such clones arise frequently, there must be a mechanism for their elimination. We have analyzed the extent of autoreactivity arising in a nonautoimmune host during the response to a foreign antigen. To overcome the process of apoptosis in primary B cells that might routinely eliminate autoreactive clones, we generated B-cell hybridomas from spleen cells of immunized mice by using a fusion partner constitutively expressing bcl-2. Multiple lines were obtained that recognize simultaneously the hapten phosphorylcholine and the self antigen double-stranded DNA. This dual specificity was not present early but was detected by day 10 after immunization. Some of these cross-reactive antibodies deposit in kidneys in a pattern similar to what is seen in autoimmune disease. These results demonstrate that autoantibodies arise at a high frequency as part of a response to foreign antigen. It has previously been shown that autoreactivity is regulated by central deletion; these data demonstrate a need for negative selection in peripheral lymphoid organs also, to regulate autoantibodies acquiring their self-specificity by somatic mutation.