Source and sink dynamics of density-dependent otter (<Emphasis Type="Italic">Lutra lutra</Emphasis>) populations in rivers of central Finland

Long-term studies were carried out in central Finland between 1985 and 2003 to examine the temporal and spatial variation in the density of otter populations. Snow tracking was used to estimate the total population and the number of litters in the study area. In total 52 otters, including 16 cubs in 11 litters, lived in the study area (1,650 km²) in 2002–2003. The otter population clearly increased during the study period. The increase in density of the otter population was sigmoid, indicating that the population had reached the local carrying capacity. The density of the population was 0.12 individuals per river ha in 1985 and 0.29 individuals per river ha in 2002. The number of cubs per litter decreased when the density of the population increased. Density-dependent offspring production, together with the auto-correlation function of growth rate, indicates intraspecific competition in otter populations. Otters in a few river systems produced most of the cubs, creating several small source populations in the entire study area. Otters in secondary (sink) habitats had a low reproduction rate. Most otters lived in river systems with large lake surfaces. The number or area of lakes within the river system correlated positively with the total number of otters, litters and cubs in the river system. The six river systems (out of 16) with the largest water area of lakes produced 81.2% of all cubs born in the study area. However, the population growth rate per river hectare or per river kilometre was equal in all kinds of river systems. Thus, among local otter populations in central Finland, a source–sink system between different habitats seems to be prevalent.     

Mobile phone radiation and the developing brain: behavioral and morphological effects in juvenile rats

The increasing use of mobile phones by children and teenagers has raised concerns about their safety. Addressing such concerns is difficult, because no data are available on possible effects from long-term exposure to radiofrequency (RF) fields during the development of the nervous system. Possible morphological and functional changes were evaluated in the central nervous system of young male Wistar rats exposed to 900 MHz mobile phone signal for 2 h/day on 5 days/week. After 5 weeks of exposure at whole-body average specific energy absorption rates of 0.3 or 3.0 W/kg or sham exposure, six rats per group were examined histologically, and the remaining 18 rats per group were subjected to behavioral tests. No degenerative changes, dying neurons, or effects on the leakage of the blood-brain barrier were detected. No group differences were observed in the open-field test, plus maze test or acoustic startle response tests. In the water maze test, however, significantly improved learning (P = 0.012) and memory (P = 0.01) were detected in rats exposed to RF fields. The results do not indicate a serious threat to the developing brain from mobile phone radiation at intensities relevant to human exposure. However, the interesting finding of improved learning and memory warrants further studies.     

Is the bryophyte soil diaspore bank buffered against nutrient enrichment and grazing exclusion?

Plant and Soil - Soil diaspore banks of bryophytes are poorly known in tundra grasslands, yet can be important for the maintenance of local bryophyte assemblages. We examined the effects of...     

Protected areas act as a buffer against detrimental effects of climate change—Evidence from large‐scale,long‐term abundance data

Climate change is driving species to shift their distributions toward high altitudes and latitudes, while habitat loss and fragmentation may hamper species ability to follow their climatic envelope. These two drivers of change may act in synergy, with particularly disastrous impacts on biodiversity. Protected areas, PAs, may thus represent crucial buffers against the compounded effects of climate change and habitat loss. However, large‐scale studies assessing the performance of PAs as such buffers remain scarce and are largely based on species occurrence data. Conversely, abundance data have proven to be more reliable for addressing changes in wildlife populations under climate change. We evaluated changes in bird abundance from the 1970s–80s to the 2000s inside and outside PAs at the trailing range edge of 30 northern bird species and at the leading range edge of 70 southern species. Abundances of retracting northern species were higher and declined less inside PAs at their trailing range edge. The positive effect of PAs on bird abundances was particularly marked in northern species that rely strongly on PAs, that is, their density distribution is largely confined within PAs. These species were nearly absent outside PAs in the 2000s. The abundances of southern species were in general lower inside PAs and increased less from the 70s–80s to 2000s. Nonetheless, species with high reliance on PAs had much higher abundances inside than outside PAs in the 2000s. These results show that PAs are essential in mitigating the retraction of northern species, but also facilitate northward expansions of southern species highly reliant on PAs. Our study provides empirical evidence documenting the role of PAs in facilitating species to adjust to rapidly changing climatic conditions, thereby contributing to the mitigation of impending biodiversity loss. PAs may thus allow time for initiating wider conservation programs on currently unprotected land.     

Packaging Strategies That Save Food: A Research Agenda for 2030

Thoroughly considering and optimizing packaging systems can avoid food loss and waste. We suggest a number of issues that must be explored and review the associated challenges. Five main issues were recognized through the extensive experience of the authors and engagement of multiple stakeholders. The issues promoted are classified as follows: (1) identify and obtain specific data of packaging functions that influence food waste; (2) understand the total environmental burden of product/package by considering the trade‐off between product protection and preservation and environmental footprint; (3) develop understanding of how these functions should be treated in environmental footprint evaluations; (4) improve packaging design processes to also consider reducing food waste; and (5) analyze stakeholder incentives to reduce food loss and waste. Packaging measures that save food will be important to fulfill the United Nations Sustainable Development goal to halve per capita global food waste at the retail and consumer levels and to reduce food losses along production and supply chains.     

WDR12, a Member of Nucleolar PeBoW-Complex,Is Up-Regulated in Failing Hearts and Causes Deterioration of Cardiac Function

Aims

In a recent genome-wide association study, WD-repeat domain 12 (WDR12) was associated with early-onset myocardial infarction (MI). However, the function of WDR12 in the heart is unknown.

Methods and Results

We characterized cardiac expression of WDR12, used adenovirus-mediated WDR12 gene delivery to examine effects of WDR12 on left ventricular (LV) remodeling, and analyzed relationship between MI associated WDR12 allele and cardiac function in human subjects. LV WDR12 protein levels were increased in patients with dilated cardiomyopathy and rats post-infarction. In normal adult rat hearts, WDR12 gene delivery into the anterior wall of the LV decreased interventricular septum diastolic and systolic thickness and increased the diastolic and systolic diameters of the LV. Moreover, LV ejection fraction (9.1%, P<0.05) and fractional shortening (12.2%, P<0.05) were declined. The adverse effects of WDR12 gene delivery on cardiac function were associated with decreased cellular proliferation, activation of p38 mitogen–activated protein kinase (MAPK)/heat shock protein (HSP) 27 pathway, and increased protein levels of Block of proliferation 1 (BOP1), essential for ribosome biogenesis. Post-infarction WDR12 gene delivery decreased E/A ratio (32%, P<0.05) suggesting worsening of diastolic function. In human subjects, MI associated WDR12 allele was associated significantly with diastolic dysfunction and left atrial size.

Conclusions

WDR12 triggers distinct deterioration of cardiac function in adult rat heart and the MI associated WDR12 variant is associated with diastolic dysfunction in human subjects.     

A comparative analysis of metacommunity types in the freshwater realm

Most metacommunity studies have taken a direct mechanistic approach, aiming to model the effects of local and regional processes on local communities within a metacommunity. An alternative approach is to focus on emergent patterns at the metacommunity level through applying the elements of metacommunity structure (EMS; Oikos, 97, 2002, 237) analysis. The EMS approach has very rarely been applied in the context of a comparative analysis of metacommunity types of main microbial, plant, and animal groups. Furthermore, to our knowledge, no study has associated metacommunity types with their potential ecological correlates in the freshwater realm. We assembled data for 45 freshwater metacommunities, incorporating biologically highly disparate organismal groups (i.e., bacteria, algae, macrophytes, invertebrates, and fish). We first examined ecological correlates (e.g., matrix properties, beta diversity, and average characteristics of a metacommunity, including body size, trophic group, ecosystem type, life form, and dispersal mode) of the three elements of metacommunity structure (i.e., coherence, turnover, and boundary clumping). Second, based on those three elements, we determined which metacommunity types prevailed in freshwater systems and which ecological correlates best discriminated among the observed metacommunity types. We found that the three elements of metacommunity structure were not strongly related to the ecological correlates, except that turnover was positively related to beta diversity. We observed six metacommunity types. The most common were Clementsian and quasi‐nested metacommunity types, whereas Random, quasi‐Clementsian, Gleasonian, and quasi‐Gleasonian types were less common. These six metacommunity types were best discriminated by beta diversity and the first axis of metacommunity ecological traits, ranging from metacommunities of producer organisms occurring in streams to those of large predatory organisms occurring in lakes. Our results showed that focusing on the emergent properties of multiple metacommunities provides information additional to that obtained in studies examining variation in local community structure within a metacommunity.     

N-linked (N-) Glycoproteomics of Urimary Exosomes*

Epithelial cells lining the urinary tract secrete urinary exosomes (40–100 nm) that can be targeted to specific cells modulating their functionality. One potential targeting mechanism is adhesion between vesicle surface glycoproteins and target cells. This makes the glycopeptide analysis of exosomes important. Exosomes reflect the physiological state of the parent cells; therefore, they are a good source of biomarkers for urological and other diseases. Moreover, the urine collection is easy and noninvasive and urinary exosomes give information about renal and systemic organ systems. Accordingly, multiple studies on proteomic characterization of urinary exosomes in health and disease have been published. However, no systematic analysis of their glycoproteomic profile has been carried out to date, whereas a conserved glycan signature has been found for exosomes from urine and other sources including T cell lines and human milk.Here, we have enriched and identified the N-glycopeptides from these vesicles. These enriched N-glycopeptides were solved for their peptide sequence, glycan composition, structure, and glycosylation site using collision-induced dissociation MS/MS (CID-tandem MS) data interpreted by a publicly available software GlycopeptideId. Released glycans from the same sample was also analyzed with MALDI-MS.We have identified the N-glycoproteome of urinary exosomes. In total 126 N-glycopeptides from 51 N-glycosylation sites belonging to 37 glycoproteins were found in our results. The peptide sequences of these N-glycopeptides were identified unambiguously and their glycan composition (for 125 N-glycopeptides) and structures (for 87 N-glycopeptides) were proposed. A corresponding glycomic analysis with released N-glycans was also performed. We identified 66 unique nonmodified N-glycan compositions and in addition 13 sulfated/phosphorylated glycans were also found. This is the first systematic analysis of N-glycoproteome of urinary exosomes.Urine is a combination of plasma filtrate and the secretion profile of cells lining the urino-genital tract. This secretion profile, in addition to proteins and metabolites, also contains exosomes and larger microvesicles that have glycoproteins on their surface. In healthy individuals, ∼70% of the urinary proteome originates from kidneys and the rest represents plasma filtered by glomeruli (1). Proteins present in urine are a collection of proteins secreted by a number of tissues, which changes in disease states (2). Therefore, the urinary proteome may serve as a rich source of biomarkers for urogenital and systemic diseases, which have been reviewed previously (3). Moreover, urine collection is a noninvasive procedure, which makes it an ideal candidate for discovery of novel biomarkers. Only a few large scale studies on urinary proteome and glycoproteome have been published (4, 5). However, most of them have not focused on the glycopeptide characterization.Microvesicles, including exosomes are secreted by many cell types and involved in functions including antigen-presentation, cell-to-cell communication, and immunomodulation (6). These are specialized compartments of cells and they mirror the physiological state of cells secreting them while also providing information about the environment into which they are secreted. For instance, the immunosuppressive and pro-angiogenic environment of cancer may be mediated partially by exosomes (6). Exosomes and other types of microvesicles are abundantly found in urine and thought to be mainly secreted by epithelial cells lining the urinary system (7). These vesicles contain DNA, RNA, and proteins.Glycosylation is an important post-translational modification of proteins and lipids and appears to play many roles, e.g. in cell adhesion, cell-to-cell communication, and immune response (8). Glycosylation is also very important for targeting of proteins to various compartments of the cells. Accordingly, glycans of glycoproteins have important roles in protein sorting to membrane microdomains and furthermore in influencing their intracellular trafficking (9). Microvesicles have a glycan signature that is distinct from the parent cell, suggesting that they originate from specialized membrane microdomains implying a role of glycosylation in microvesicle protein sorting (10, 11). Changes in N-glycans of exosomes from expressed prostatic secretions correlate with disease severity (12). HIV-1 particles were found to have a glycome (the comprehensive glycan profile of a protein, cell, or tissue) largely shared with microvesicles, which is taken to imply that the virus hijacks the glycomachinery of infected cells and uses it systematically to infect additional cells or to deceive the normal immunodefence (13). Thus, the specific glycoproteins of exosomes may be of major impact in targeting exosomes to distinct cells and tissues.Exosome uptake in various cell types has been shown to occur through the mechanisms of clathrin-mediated endocytosis, phagocytosis, and micropinocytosis (14, 15). The uptake of exosomes by dendritic cells and macrophages has been shown to be inhibited by mannose, N-acetylglucosamine, and lactose residues, respectively. This uptake is mediated by a C-type lectin in dendritic cells and galectin-5 in macrophages (14, 15). All this points toward a system in which the exosome glycosylation pattern is kept specific by the cells secreting them to suit the target cell makeup and uptake pathways, and further downstream functions. Taken together, these findings suggest that better understanding of surface glycosylation patterns as well as the glycomics and glycoproteomics of exosomes might help in establishing the specificity of exosome uptake by target cells and activated downstream pathways. This information about exosome uptake might be utilized in therapeutics involving exosomes. Glycome and glycoproteome of urinary microvesicles will provide information not only about the functional state of constituent proteins, but it will also highlight the similarities and differences among proteins that are specifically targeted to exosomes.An N-glycopeptide analysis using collision induced dissociation (CID)-Tandem MS has been reported previously for different sample types (16, 17). This approach provides information about the composition of glycan, partial structure, glycosylation site, and peptide sequence from the same molecule compared with approaches where released glycans or peptides of N-glycopeptides are analyzed separately.We have published an algorithm for an automated analysis of N-glycopeptides (18, 19). A public, web-based software with some changes to the original was developed and named as GlycopeptideId (www.appliednumerics.com, GlycopeptideID version 28–02-28 0.91 beta). The major change was to analyze glycan structures against a database and not with an iterative de novo glycan structure analysis. The proposed structures were further manually validated by the presence of diagnostic ions, when they were available for the given structure.This software was utilized in this study and a comprehensive glycopeptide characterization of urinary exosomal glycoproteins was carried out. We report here the glycan structure determination of urinary exosomal glycoproteins. We have characterized 126 N-glycopeptides representing 51 N-glycosylation sites that belong to 37 glycoproteins. Additionally, glycomic analysis of released N-glycans was also performed and 66 unique modified and 13 sulfated and/or phosphorylated glycans were found. A third of total glycan compositions were common to both the analysis, whereas approximately a third were unique to both the analysis.     

Macoma balthica in the White and Barents Seas: properties of a widespread marine hybrid swarm (Mollusca: Bivalvia)

A main molecular subdivision in the circumpolar Macoma balthica complex has been described between Atlantic and Pacific taxa. In NE Europe, the clams of the White and Barents Seas, however, show deviant genetic structures. Using allozyme and mitochondrial DNA data, we explore the hypothesis that these deviations result from hybridization between an Atlantic (M. b. rubra) and an invading Pacific (M. b. balthica) lineage. A practically pure Atlantic Macoma extends from France north to the Varanger Peninsula (NE Norway), whereas populations farther east have genetic compositions intermediate between true Atlantic and true Pacific. Admixture estimates range from 32 to 90% Pacific contribution, with a notable deviation in a nearly pure Atlantic outpost in the Mezen Bay (NE White Sea). The pattern of variation is not one of a simple collinear mixing however. Different characters exhibit different degrees of introgression, and the relative introgression varies regionally. Yet, there are practically no interlocus genotypic disequilibria between the diverged loci, which brings out the White Sea-Barents Sea M. balthica as the best-documented marine animal hybrid swarms so far, arisen through amalgamation of genomes previously isolated since pre-Pleistocene times. On top of the main admixture pattern, strong geographical structuring is also seen in characters unrelated to the principal systematic distinction. The persistence of the regional patterns indicates restricted gene flow at the present time, despite the high dispersal potential of the species. The causes of this structuring could be in a complex history of colonization events and features of local hydrography enhancing isolation and divergence of populations.