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openCustomJan 2020View details →

Seedling recruitment in artificial gaps

We examined the role of both intermediate-sized gaps and a dense shrub layer on subsequent tree seedling recruitment in a southern Appalachian deciduous forest. We monitored the density of tree seedlings in twelve artificial gaps and adjacent canopy controls under two contrasting understory conditions. Half of the experimental gaps were dominated by the dense, shade-producing shrub, Rhododendron maximum, while the remaining gaps were relatively open. Canopy gaps 20 m in diameter were created by girdling canopy trees, leaving standing dead trees with minimal disturbance to the understory. Density of first-year and first-year seedlings was monitored in transects extending from adjacent undisturbed forest through the experimental gaps.

openCustomJan 2020View details →

Probing the mechanisms by which sub-canopy evergreen shrubs inhibit tree seedling recruitment at the Coweeta Hydrologic Laboratory from 1999 to 2003

Two hundred 2x2 meter plots along transects and traversing 3 understory conditions; rhododendron, kalmia, open. Light conditions will be assessed for each plot and the extreme 50% will be used for experimentation. All plots will be planted to a combination of northern red oak, chestnut oak, red maple, and pitch pine. Inoculated (with mychorrizae) and non-inoculated seedlings will be planted in the plots. Relationships between performance and mychorrizal infection will be determined.

openCustomJan 2020View details →

Recruitment potential of southern and local tree species at the Coweeta Hydrologic Laboratory from 2003 to 2005

For the Southeast US, biogeography models predict an increase in aridity with vegetation changes from temperate deciduous forest to southern mixed forest if there are moderate temperature increases, or to savanna landscapes under drier scenarios (Bachelet et al. 2001). Given this forecast, I hypothesize that the colonization potential of coastal and more southern species in the North Carolina Piedmont and southern Appalachians will be enhanced by a warmer and drier climate. The nature of this vegetation shift will mainly depend on the adaptability of these species to the specific characteristics of the sites. Considering that recruitment is the limiting stage for successful establishment of tree populations (Harper 1977), I propose to study recruitment limitation of potential migrant species relative to local trees in two regions in North Carolina, the Piedmont and the southern Appalachian mountains. Experimental manipulations will allow the quantification of recruitment potential of non-native tree species and their performance with respect to native species. Field and greenhouse experiments will be used to develop and parameterize a model of community recruitment. I will employ the model to elucidate potential changes in forest species composition under a suite of future climate scenarios. Both data and modeling work are expected to improve our understanding about the mechanisms that may be involved in restructuring communities in the face of a changing climate.

openCustomFeb 2012View details →

MCR LTER: Coral Reef: Diadema predation and recruitment in Moorea, French Polynesia

These are field data from Moorea, French Polynesia regarding the population dynamics of Diadema savignyi. Data were collected during the austral winters in 2009 and 2010. Four datasets are provided: (1) recruitment data of Diadema savignyi over the course of ~9 weeks during the austral winter of 2010, (2) predation data of adult Diadema using a tethering experiment, (3) urchin abundance surveys for 2009 and 2010, and (4) a 9 week weekly survey of newly recruited Diadema (test diameter). These data are part of a PhD dissertation, "Herbivore Community Dynamics and Functional Compositions in Moorea, French Polynesia", 2014, published by ProQuest.

openCustomNov 2015View details →

MCR LTER: Coral Reef: Population Dynamics: Mean Daily Recruitment of Three-spot Dascyllus to Gump Reef, 1992 to 2012

These data describe the abundance of settler-stage three-spot dascyllus (Dascyllus trimaculatus), a planktivorous damselfish to their juvenile microhabitat, the sea anemone Heteractis magnifica. Surveys were begun in 1993, and, except for 1994, have been conducted daily each year between June and September on a reef adjacent to the UC Berkeley Gump Research Station in Cooks Bay on the north shore of the island of Moorea in French Polynesia. This time series completed in 2012.

openCustomSep 2017View details →

MCR LTER: Coral Reef: Recruitment during El Niño, Edmunds PLOS1 2017

The negative implications of the thermal sensitivity of reef corals became clear with coral bleaching throughout the Caribbean in the 1980’s, and later globally, with the severe El Niño of 1998 and extensive seawater warming in 2005. These events have substantially contributed to declines in coral cover, and therefore the El Niño of 2016 raised concerns over the implications for coral reefs; on the Great Barrier Reef these concerns have been realized. A different outcome developed in Mo’orea, French Polynesia, where in situ seawater temperature from 15 March 2016 to 15 April 2016 was an average of 0.4°C above the upper 95% CI of the decadal mean temperature, and the NOAA Degree Heating Weeks (DHW) metric supported a Level 1 bleaching alert (DHW ≥ 4.0). Starting 1 September 2016 and for the rest of the year (122 d), in situ seawater temperature was an average of 0.4°C above the 95% CI of long-term values, although DHW remained at zero. Minor coral bleaching (0.2–2.6% of the coral) occurred on the outer reef (10-m and 17-m depth) in April 2016, by May 2016 it had intensified to affect 1.3– 16.8% of the coral, but by August 2016, only 1.4–3.0% of the coral was bleached. Relative to the previous decade, recruitment of scleractinians to settlement tiles on the outer- (10 m) and back- (2 m) reef over 2016/17 was high, both from January 2016 to August 2016, and from August 2016 to January 2017, with increased relative abundances of pocilloporids on the outer reef, and acroporids in the back reef. The 2016 El Niño created a distinctive signature in seawater temperature for Mo’orea, but it did not cause widespread coral bleaching or mortality, rather, it was associated with high coral recruitment. While the 2016 El Niño has negatively affected other coral reefs in the Indo-Pacific, the coral communities of Mo’orea continue to show signs of resilience, thus cautioning against general statements regarding the effects of the 2015/16 El Niño on coral reefs in the region. This wo

opencc-by-4.0Feb 2020View details →

MiRoR4_P1_A systematic review describes models for recruitment prediction at the design stage of a clinical trial

This dataset is related to the publication "A systematic review describes models for recruitment prediction at the design stage of a clinical trial".

opencc-by-4.0Apr 2020View details →

ACKR4 Recruits GRK3 Prior to β-arrestins but Can Scavenge Chemokines in the Absence of β-arrestins

Chemokines are essential for guiding cell migration. Atypical chemokine receptors (ACKRs) contribute to the cell migration process by binding, internalizing and degrading local chemokines, which enables the formation of confined gradients. ACKRs are heptahelical membrane spanning molecules structurally related to G-protein coupled receptors (GPCRs), but seem to be unable to signal through G-proteins upon ligand binding. ACKR4 internalizes the chemokines CCL19, CCL21, and CCL25 and is best known for shaping functional CCL21 gradients. Ligand binding to ACKR4 has been shown to recruit β-arrestins that has led to the assumption that chemokine scavenging relies on β-arrestin-mediated ACKR4 trafficking, a common internalization route taken by class A GPCRs. Here, we show that CCL19, CCL21, and CCL25 readily recruited β-arrestin1 and β-arrestin2 to human ACKR4, but found no evidence for β-arrestin-dependent or independent ACKR4-mediated activation of the kinases Erk1/2, Akt, or Src. However, we demonstrate that β-arrestins interacted with ACKR4 in the steady-state and contributed to the spontaneous trafficking of the receptor in the absence of chemokines. Deleting the C-terminus of ACKR4 not only interfered with the interaction of β-arrestins, but also with the uptake of fluorescently labeled cognate chemokines. We identify the GPCR kinase GRK3, and to a lesser extent GRK2, but not GRK4, GRK5, and GRK6, to be recruited to chemokine-stimulated ACKR4. We show that GRK3 recruitment preceded the recruitment of β-arrestins upon ACKR4 engagement and that GRK2/3 inhibition partially interfered with steady-state interaction and chemokine-driven recruitment of β-arrestins to ACKR4. Overexpressing β-arrestin2 accelerated the uptake of fluorescently labeled CCL19, indicating that β-arrestins contribute to the chemokine scavenging activity of ACKR4. By contrast, cells lacking β-arrestins were still capable to take up fluorescently labeled CCL19 demonstrating that β-arrestins are dispensable for chemokine scavenging by ACKR4.

opencc-by-4.0Nov 2020View details →

5 Benefits of Utilising A Recruitment Agency

Save time and money by seeking the help of a<a href="https://www.nextdayrecruitment.com.au/"> recruitment agency Sydney</a> for all your hiring needs. Trust that they can provide you with the most suitable candidates for your needs. #RecruitmentAgencySydney

opencc-by-4.0Jan 2021View details →

3 Tips For Choosing The Right Recruitment Agency

If you're a company looking for the right <a href="https://www.nextdayrecruitment.com.au/">recruitment agency Northern Beaches</a> to help you find candidates that will best fit your hiring needs and budget, you have to see these important tips.

opencc-zeroDec 2018View details →

Data from: Microsite conditions in retrogressive thaw slumps may facilitate increased seedling recruitment in the Alaskan Low Arctic

In Low Arctic tundra, thermal erosion of ice-rich permafrost soils (thermokarst) has increased in frequency since the 1980s. Retrogressive thaw slumps (RTS) are thermokarst disturbances forming large open depressions on hillslopes through soil wasting and vegetation displacement. Tall (> 0.5 m) deciduous shrubs have been observed in RTS a decade after disturbance. RTS may provide conditions suitable for seedling recruitment, which may contribute to arctic shrub expansion. We quantified in situ seedling abundance, and size and viability of soil seedbanks in greenhouse trials for two RTS chronosequences near lakes on Alaska's North Slope. We hypothesized recent RTS provide microsites for greater recruitment than mature RTS or undisturbed tundra. We also hypothesized soil seedbanks demonstrate quantity-quality trade-offs: younger seedbanks contain smaller numbers of mostly viable seed that decrease in viability as seed accumulates over time. We found five times as many seedlings in younger RTS as in older RTS, including birch and willow, and no seedlings in undisturbed tundra. Higher seedling counts were associated with bare soil, warmer soils, higher soil available nitrogen, and less plant cover. Seedbank viability was unrelated to size. Older seedbanks were larger at one chronosequence, with no difference in percent germination. At the other chronosequence, germination was lower from older seedbanks but seedbank size was not different. Seedbank germination was positively associated with in situ seedling abundance at one RTS chronosequence, suggesting post-disturbance revegetation from seedbanks. Thermal erosion may be important for recruitment in tundra by providing bare microsites that are warmer, more nutrient rich, and less vegetated than in undisturbed conditions. Differences between two chronosequences in seedbank size, viability, and species composition suggest disturbance interacts with local conditions to form seedbanks. RTS may act as seedling nurseries to benefit many arctic species as climate changes, particularly those that do not produce persistent seed.

opencc-zeroNov 2023View details →

Male song structure predicts offspring recruitment to the breeding population in a migratory bird

Bird song is a classic example of a sexually selected trait, but much of the work relating individual song components to fitness has not accounted for song typically being composed of multiple, often-correlated components, necessitating a multivariate approach. We explored the role of sexual selection in shaping complex male song of house wrens (Troglodytes aedon) by simultaneously relating its multiple components to fitness using multivariate selection analysis, which is widely used in insect and anuran studies but not in birds. The analysis revealed significant variation in the form and strength of selection acting on song across different selection episodes, from nest-site defense to recruitment of offspring to the breeding population. Males that sang more song typically employed in close communication sired more offspring that were subsequently recruited to the breeding population than those that sang far-communication song. However, this relationship was not consistent across earlier selection episodes, as evidenced by non-linear selection acting on these song components in other contexts. Collectively, our results present a complex picture of multivariate selection on male song structure that would not be evident using univariate approaches and suggest possible trade-offs within and among song components at different points of the breeding season.

opencc-zeroNov 2023View details →

Data from: The mechanism of promoting rhizosphere nutrient turnover for arbuscular mycorrhizal fungi attribute to recruited functional bacterial assembly

Symbiosis with arbuscular mycorrhizal (AM) fungi improves plant nutrient capture from the soil, yet there is limited knowledge about the diversity, structure, functioning, and assembly processes of AM fungi-related microbial communities. Here, 16S rRNA gene sequencing and metagenomic sequencing were used to detect bacteria in the rhizosphere of Lotus japonicus inoculated with and without AM fungi, and the L. japonicus mutant ljcbx (defective in symbiosis) inoculated with AM fungi in southern grassland soil. Our results show that AM symbiosis significantly increased bacterial diversity and promoted deterministic processes of bacterial community construction, suggesting that mycorrhizal symbiosis resulted in the directional enrichment of bacterial communities and established a stable rhizosphere bacterial community. AM fungi promoted the enrichment of nine bacteria, including Ohtaekwangia, Niastella, Gemmatimonas, Devosia, Sphingomonas, Novosphingobium, Opitutus, Lysobacter, Brevundimonas, which are positively correlated with NPK-related parameters. Through a functional identification experiment, we found that six of these genera, including Brevundimonas, Lysobacter, Ohtaekwangia, Sphingomonas, Devosia, and Gemmatimonas, demonstrated the ability to mineralize organophosphate and dissolve inorganic phosphorus, nitrogen, and potassium. Our study revealed that AM fungi can regulate rhizosphere bacterial community assembly and attract specific rhizosphere bacteria to promote soil nutrient turnover in southern grasslands.

opencc-zeroMar 2024View details →

Image quantification data for: Activity-dependent mitochondrial ROS signaling regulates recruitment of glutamate receptors to synapses

Our understanding of mitochondrial signaling in the nervous system has been limited by the technical challenge of analyzing mitochondrial function in vivo. In the transparent genetic model Caenorhabditis elegans, we were able to manipulate and measure mitochondrial ROS (reactive oxygen species) signaling of individual mitochondria as well as neuronal activity of single neurons in vivo. Using this approach, we provide evidence supporting a novel role for mitochondrial ROS signaling in dendrites of excitatory glutamatergic C. elegans interneurons. Specifically, we show that following neuronal activity, dendritic mitochondria take up calcium (Ca2+) via the mitochondrial Ca2+ uniporter MCU-1 which results in an upregulation of mitochondrial ROS production. We also observed that mitochondria are positioned in close proximity to synaptic clusters of GLR-1, the C. elegans ortholog of the AMPA subtype of glutamate receptors that mediate neuronal excitation. We show that synaptic recruitment of GLR-1 is upregulated when MCU-1 function is pharmacologically or genetically impaired but is downregulated by mitoROS signaling. Thus, signaling from postsynaptic mitochondria may regulate excitatory synapse function to maintain neuronal homeostasis by preventing excitotoxicity and energy depletion.

opencc-by-4.0Oct 2023View details →

F I G U R E 1 in Evidence of successful recruitment of non-native pink salmon Oncorhynchus gorbuscha in Iceland

F I G U R E 1 Distribution of pink salmon Oncorhynchus gorbuscha in Iceland. (a) Location of rivers in Iceland with reported catches of adult O. gorbuscha in 2000, 2005, and annually from 2015 according to Bárðarson et al. (2022), and (b) locations of fishing surveys in 2022 to catch smolts of O. gorbuscha in three rivers of southwest Iceland

Figure 3 in Fucus vesiculosus adapted to a life in the Baltic Sea: impacts on recruitment, growth, re-establishment and restoration

Figure 3: Boxplot showing number of Fucus vesiculosus juveniles per dm2 surviving from mid-July to early November, 1994 in Askö. Treatments in (A) "Manipulated Fucus" without understorey (diagonal stripes) and "Natural Fucus (control)" with understorey (white) and (B) "Cladophora-covered substratum" (chequered) and "Cleaned substratum" cleared from both Fucus and understorey vegetation (vertical stripes). Note major difference in scales for y-axes in each panel. n = 6 for all treatments. *indicates significant difference in density of juveniles between two treatments at one date (p <0.05). One-way ANOVA of treatments at each date showed a higher number of juveniles in treatments containing Fucus (i.e. Figure 3A) on all dates compared to treatments without Fucus (i.e. Figure 3B; p <0.001).

Figure 1 in Fucus vesiculosus adapted to a life in the Baltic Sea: impacts on recruitment, growth, re-establishment and restoration

Figure 1: Maps showing areas and sites for field experiments presented in this paper. (A) Map of the Baltic Sea showing areas 1–5. (B) Area 1 with Sites A–G outside Trosa town (black) and Area 2 with control Site H near Askö laboratory on Askö island. (C) Area 5 with Sites I–J in Gdansk Bay.

Figure 2 in Fucus vesiculosus adapted to a life in the Baltic Sea: impacts on recruitment, growth, re-establishment and restoration

Figure 2: Fucus vesiculosus increase in size over time during 4 years. Fucus vesiculosus: volume (calculated as a cone from thallus height and circumference) plotted against biomass (g dry weight) with linear regression for (A) 1-year-old, (B) 2-year-old, (C) 3-year-old and (D) 4-year-old thalli grown in the field at Askö during 1991–1994.

Figure 5 in Fucus vesiculosus adapted to a life in the Baltic Sea: impacts on recruitment, growth, re-establishment and restoration

Figure 5: Boxplot showing germination (%) of Fucus vesiculosus zygotes after 7 days of exposure under laboratory conditions to exudates from Cladophora glomerata, Ulva intestinalis, Pylaiella littoralis, Ceramium tenuicorne and Hildenbrandia rubra. All treatments differed (p <0.001) from the control (one way ANOVA). n = 6 for all treatments.

Figure 4 in Fucus vesiculosus adapted to a life in the Baltic Sea: impacts on recruitment, growth, re-establishment and restoration

Figure 4: Boxplot showing number of Fucus vesiculosus juveniles per dm2 on five different types of substratum. (A) Askö, after 5 months, n = 10 except ceramic tile (n = 7) and Hildenbrandia treatment (n = 9). (B) Räfsnäs after 4 months, sample size n = 6. Note major difference in scales for y-axes in each panel. Letters (A–E) above bars show groups that differ significantly (at p = 0.05) within each site according to Tukey HSD post hoc test.