scholarly journals Flowers up! The effect of floral height along the shoot axis on the fitness of bat-pollinated species

2019 ◽  
Vol 124 (5) ◽  
pp. 809-818 ◽  
Author(s):  
Ugo M Diniz ◽  
Arthur Domingos-Melo ◽  
Isabel Cristina Machado
Keyword(s):  
Linear Models ◽  
Specific Effect ◽  
Mixed Effect ◽  
Bat Pollination ◽  
Nectar Feeding ◽  
Flower Traits ◽  
Species Specific ◽  
Important System ◽  
Inflorescence Length

Abstract Background and Aims Bat-pollination is an important system in terms of occurrence and distribution, although it remains little studied. Thus, the role of particular flower traits in this interaction remains uncertain. Flower height along the shoot axis, associated with flower exposure, has often been deemed a key trait in this system, but its effect on fitness has not previously been assessed. We aimed to test its role and propose that taller flowers attain higher fitness due to a higher degree of accessibility and conspicuity to foraging bats. Methods We assessed the effect of floral height on bat visiting rates to individual flowers of Crescentia cujete (Bignoniaceae), a cauliflorous model bat-pollinated species with a marked gradient in flower height along the shoot axis. Additionally, we tested the effect of this variable on seed/ovule ratio measurements from seven other species from different families along a herb–tree gradient. Hypotheses were tested through mixed-effect linear models. Key Results Bat visiting rates varied positively as a function of flower height in C. cujete, but significance was found only for the subset of flowers located on the trunk, closer to the ground. Similarly, seed/ovule ratios were positively correlated with flower height only for the three species with the shortest statures along the height gradient and shortest average floral heights. These results suggest that proximity to the ground, associated with herbaceous or bushy surrounding vegetation, may be an obstacle to the foraging of nectar-feeding bats, which in turn should explain the morphological convergence of inflorescence length and exposure strategies of short-statured bat-pollinated plants. Conclusions Flower height has a species-specific effect on plant fitness. This study provides a novel numerical perspective to the role of an unexplored trait in bat-pollination, and has elucidated some aspects of the adaptive importance of flower height based on limitations imposed by ecologically complex pollinators.

scholarly journals Wider-community Segregation and the Effect of Neighbourhood Ethnic Diversity on Social Capital: An Investigation into Intra-Neighbourhood Trust in Great Britain and London

Sociology ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 1011-1033 ◽  
Author(s):  
James Laurence
Keyword(s):  
Social Capital ◽  
Great Britain ◽  
Ethnic Diversity ◽  
Linear Models ◽  
Critical Role ◽  
Hierarchical Linear Models ◽  
Negatively Associated ◽  
Community Segregation ◽  
Do So

Extensive research has demonstrated that neighbourhood ethnic diversity is negatively associated with intra-neighbourhood social capital. This study explores the role of segregation and integration in this relationship. To do so it applies three-level hierarchical linear models to two sets of data from across Great Britain and within London, and examines how segregation across the wider-community in which a neighbourhood is nested impacts trust amongst neighbours. This study replicates the increasingly ubiquitous finding that neighbourhood diversity is negatively associated with neighbour-trust. However, we demonstrate that this relationship is highly dependent on the level of segregation across the wider-community in which a neighbourhood is nested. Increasing neighbourhood diversity only negatively impacts neighbour-trust when nested in more segregated wider-communities. Individuals living in diverse neighbourhoods nested within integrated wider-communities experience no trust-penalty. These findings show that segregation plays a critical role in the neighbourhood diversity/trust relationship, and that its absence from the literature biases our understanding of how ethnic diversity affects social cohesion.

scholarly journals Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2036
Author(s):  
Luigi Marongiu ◽  
Markus Burkard ◽  
Sascha Venturelli ◽  
Heike Allgayer
Keyword(s):  
Structural Damage ◽  
Folk Medicine ◽  
Gastrointestinal Diseases ◽  
Potential Contribution ◽  
Anticancer Properties ◽  
Specific Phage ◽  
Microbial Network ◽  
Inflammatory Bowel ◽  
Species Specific

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.

scholarly journals A Role for Histone H2B During Repair of UV-Induced DNA Damage in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1375-1387
Author(s):  
Emmanuelle M D Martini ◽  
Scott Keeney ◽  
Mary Ann Osley
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Chromatin Structure ◽  
Specific Effect ◽  
Cell Killing ◽  
Cyclobutane Pyrimidine Dimers ◽  
Histone H2b ◽  
Uv Sensitivity ◽  
Pyrimidine Dimers

Abstract To investigate the role of the nucleosome during repair of DNA damage in yeast, we screened for histone H2B mutants that were sensitive to UV irradiation. We have isolated a new mutant, htb1-3, that shows preferential sensitivity to UV-C. There is no detectable difference in bulk chromatin structure or in the number of UV-induced cis-syn cyclobutane pyrimidine dimers (CPD) between HTB1 and htb1-3 strains. These results suggest a specific effect of this histone H2B mutation in UV-induced DNA repair processes rather than a global effect on chromatin structure. We analyzed the UV sensitivity of double mutants that contained the htb1-3 mutation and mutations in genes from each of the three epistasis groups of RAD genes. The htb1-3 mutation enhanced UV-induced cell killing in rad1Δ and rad52Δ mutants but not in rad6Δ or rad18Δ mutants, which are defective in postreplicational DNA repair (PRR). When combined with other mutations that affect PRR, the histone mutation increased the UV sensitivity of strains with defects in either the error-prone (rev1Δ) or error-free (rad30Δ) branches of PRR, but did not enhance the UV sensitivity of a strain with a rad5Δ mutation. When combined with a ubc13Δ mutation, which is also epistatic with rad5Δ, the htb1-3 mutation enhanced UV-induced cell killing. These results suggest that histone H2B acts in a novel RAD5-dependent branch of PRR.

scholarly journals Species-Specific Regulation of TRPM2 by PI(4,5)P2 via the Membrane Interfacial Cavity

2021 ◽  
Vol 22 (9) ◽  
pp. 4637
Author(s):  
Daniel Barth ◽  
Andreas Lückhoff ◽  
Frank J. P. Kühn
Keyword(s):  
Amino Acid Residues ◽  
Hek 293 ◽  
Complete Inactivation ◽  
293 Cells ◽  
Activation Mechanisms ◽  
Specific Regulation ◽  
Species Specific ◽  
Inside Out ◽  
Positively Charged

The human apoptosis channel TRPM2 is stimulated by intracellular ADR-ribose and calcium. Recent studies show pronounced species-specific activation mechanisms. Our aim was to analyse the functional effect of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), commonly referred to as PIP2, on different TRPM2 orthologues. Moreover, we wished to identify the interaction site between TRPM2 and PIP2. We demonstrate a crucial role of PIP2, in the activation of TRPM2 orthologues of man, zebrafish, and sea anemone. Utilizing inside-out patch clamp recordings of HEK-293 cells transfected with TRPM2, differential effects of PIP2 that were dependent on the species variant became apparent. While depletion of PIP2 via polylysine uniformly caused complete inactivation of TRPM2, restoration of channel activity by artificial PIP2 differed widely. Human TRPM2 was the least sensitive species variant, making it the most susceptible one for regulation by changes in intramembranous PIP2 content. Furthermore, mutations of highly conserved positively charged amino acid residues in the membrane interfacial cavity reduced the PIP2 sensitivity in all three TRPM2 orthologues to varying degrees. We conclude that the membrane interfacial cavity acts as a uniform PIP2 binding site of TRPM2, facilitating channel activation in the presence of ADPR and Ca2+ in a species-specific manner.

scholarly journals Relationship between Cycling Infrastructure and Transportation Cycling in a Small Urban Area

2021 ◽  
Vol 1 (1) ◽  
pp. 99-112
Author(s):  
Richard Larouche ◽  
Nimesh Patel ◽  
Jennifer L. Copeland
Keyword(s):  
Generalized Linear Models ◽  
Qualitative Data ◽  
Linear Models ◽  
The Other ◽  
Small City ◽  
The Road ◽  
The Past ◽  
Low Prevalence ◽  
The Relationship

The role of infrastructure in encouraging transportation cycling in smaller cities with a low prevalence of cycling remains unclear. To investigate the relationship between the presence of infrastructure and transportation cycling in a small city (Lethbridge, AB, Canada), we interviewed 246 adults along a recently-constructed bicycle boulevard and two comparison streets with no recent changes in cycling infrastructure. One comparison street had a separate multi-use path and the other had no cycling infrastructure. Questions addressed time spent cycling in the past week and 2 years prior and potential socio-demographic and psychosocial correlates of cycling, including safety concerns. Finally, we asked participants what could be done to make cycling safer and more attractive. We examined predictors of cycling using gender-stratified generalized linear models. Women interviewed along the street with a separate path reported cycling more than women on the other streets. A more favorable attitude towards cycling and greater habit strength were associated with more cycling in both men and women. Qualitative data revealed generally positive views about the bicycle boulevard, a need for education about sharing the road and for better cycling infrastructure in general. Our results suggest that, even in smaller cities, cycling infrastructure may encourage cycling, especially among women.

Closing Achievement Gaps: Examining the Roles of School Background and Process

2021 ◽  
pp. 001312452198944
Author(s):  
Huang Wu ◽  
Jianping Shen ◽  
Jessaca Spybrook ◽  
Xingyuan Gao
Keyword(s):  
Achievement Gap ◽  
Teacher Collaboration ◽  
White Students ◽  
Science Achievement ◽  
Linear Models ◽  
Achievement Gaps ◽  
School Level ◽  
Academic Learning ◽  
Closing Achievement Gaps

The purpose of this study was to examine the role of school background and school process in closing achievement gaps between White and non-White students in science. To answer the research questions, a series of two-level hierarchical linear models (HLM) was performed on the fourth-grade U.S. portion of the 2015 Trends in International Mathematics and Science Study (TIMSS) data. Results indicate that (a) the science achievement gap between White and non-White students is 0.21 standard deviation, holding student and school background constant; (b) the science achievement gap varies across schools; (c) none of the school background variables are associated with the achievement gap in a school; and (d) school emphasis on student academic learning is not only associated with higher school-level science achievement, but also with a narrower science achievement gap between White and non-White students. However, teacher collaboration is not associated with school-level science achievement but is associated with a larger achievement gap. Implications, limitations, and recommendations for further research are discussed.

scholarly journals Sialic Acids as Receptors for Pathogens

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 831
Author(s):  
Patrycja Burzyńska ◽  
Łukasz F. Sobala ◽  
Krzysztof Mikołajczyk ◽  
Marlena Jodłowska ◽  
Ewa Jaśkiewicz
Keyword(s):  
Malaria Parasite ◽  
Sialic Acids ◽  
Influenza Viruses ◽  
Disease Vectors ◽  
Animal Disease ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Infection Biology ◽  
Species Specific

Carbohydrates have long been known to mediate intracellular interactions, whether within one organism or between different organisms. Sialic acids (Sias) are carbohydrates that usually occupy the terminal positions in longer carbohydrate chains, which makes them common recognition targets mediating these interactions. In this review, we summarize the knowledge about animal disease-causing agents such as viruses, bacteria and protozoa (including the malaria parasite Plasmodium falciparum) in which Sias play a role in infection biology. While Sias may promote binding of, e.g., influenza viruses and SV40, they act as decoys for betacoronaviruses. The presence of two common forms of Sias, Neu5Ac and Neu5Gc, is species-specific, and in humans, the enzyme converting Neu5Ac to Neu5Gc (CMAH, CMP-Neu5Ac hydroxylase) is lost, most likely due to adaptation to pathogen regimes; we discuss the research about the influence of malaria on this trait. In addition, we present data suggesting the CMAH gene was probably present in the ancestor of animals, shedding light on its glycobiology. We predict that a better understanding of the role of Sias in disease vectors would lead to more effective clinical interventions.

Life Course Socioeconomic Position, Intergenerational Social Mobility, and Hypertension Incidence in ELSA-Brasil

2021 ◽  
Author(s):  
José Aparecido Soares Lopes ◽  
Luana Giatti ◽  
Rosane Harter Griep ◽  
Antonio Alberto da Silva Lopes ◽  
Sheila Maria Alvim Matos ◽  
...  
Keyword(s):  
Life Course ◽  
Social Mobility ◽  
Socioeconomic Position ◽  
Linear Models ◽  
Sociodemographic Factors ◽  
Incidence Rates ◽  
Explanatory Variables ◽  
Rate Ratios

Abstract Background Life course epidemiology is a powerful framework to unravel the role of socioeconomic position (SEP) disparities in hypertension (HTN). This study investigated whether life course SEP is associated with HTN incidence. Specifically, to test whether cumulative low SEP throughout life and unfavorable intergenerational social mobility increased HTN incidence. METHODS Longitudinal analysis of 8,754 ELSA-Brasil participants without HTN or cardiovascular in visit 1 (2008–2010). The response variable was the incidence of HTN between visits 1 and 2 (2012–2014). The explanatory variables were childhood, youth, and adulthood SEP, cumulative low SEP, and intergenerational social mobility. Associations were estimated by incidence rate ratios (IRRs) obtained by generalized linear models, with Poisson distribution and logarithmic link function, after adjustment for sociodemographic, behavioral, and health factors. RESULTS The incidence of HTN was 43.2/1,000 person-years, being higher in males, elderly (70–74 years), self-declared black, and low SEP individuals. After considering sociodemographic factors, low SEP in childhood, youth, and adulthood remained statistically associated with increased HTN incidence. Individuals in the third (IRR: 1.26; 95% confidence interval (CI): 1.11–1.44) and fourth top quartiles (IRR: 1.29; 95% CI: 1.11–1.49) of cumulative low SEP, vs. first, as well as those with low stable intergenerational trajectory (IRR: 1.29; 95% CI: 1.16–1.43), vs. high stable, also had increased HTN incidence rates. Conclusions Socioeconomic disparities at all phases of the life cycle appear to raise HTN incidence rates, being the individuals with greater accumulation of exposure to low SEP and with more unfavorable intergenerational mobility at greatest risk, even in a short follow-up time.

scholarly journals An Exon-Based Comparative Variant Analysis Pipeline to Study the Scale and Role of Frameshift and Nonsense Mutation in the Human-Chimpanzee Divergence

2009 ◽  
Vol 2009 ◽  
pp. 1-19 ◽  
Author(s):  
GongXin Yu
Keyword(s):  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Cell Lineage ◽  
Nonsense Mutations ◽  
Less Is More ◽  
Sequencing Errors ◽  
Evolutionary Force ◽  
Variant Analysis ◽  
Species Specific

Chimpanzees and humans are closely related but differ in many deadly human diseases and other characteristics in physiology, anatomy, and pathology. In spite of decades of extensive research, crucial questions about the molecular mechanisms behind the differences are yet to be understood. Here I reportExonVar, a novel computational pipeline forExon-based human-chimpanzee comparativeVariant analysis. The objective is to comparatively analyze mutations specifically those that caused the frameshift and nonsense mutations and to assess their scale and potential impacts on human-chimpanzee divergence. Genomewide analysis of human and chimpanzee exons withExonVaridentified a number of species-specific, exon-disrupting mutations in chimpanzees but much fewer in humans. Many were found on genes involved in important biological processes such as T cell lineage development, the pathogenesis of inflammatory diseases, and antigen induced cell death. A “less-is-more” model was previously established to illustrate the role of the gene inactivation and disruptions during human evolution. Here this analysis suggested a different model where the chimpanzee-specific exon-disrupting mutations may act as additional evolutionary force that drove the human-chimpanzee divergence. Finally, the analysis revealed a number of sequencing errors in the chimpanzee and human genome sequences and further illustrated that they could be corrected without resequencing.

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