Role of Sibling Aggression in Food Distribution to Nestling Cattle Egrets (Bubulcus Ibis)

The Auk ◽  
1986 ◽  
Vol 103 (4) ◽  
pp. 768-776 ◽  
Author(s):  
Bonnie J. Ploger ◽  
Douglas W. Mock
Keyword(s):  
Bird Species ◽  
Food Distribution ◽  
Sibling Aggression ◽  
Bubulcus Ibis ◽  
Main Effect ◽  
Ultimate Cause ◽  
Access To Food

Abstract Sibling aggression occurs in a wide variety of asynchronously hatching bird species. In some, fights among siblings lead inevitably to death, in which case the benefits of winning are clear. In species where sibling aggression is common but usually not fatal, the benefits gained by winning and the methods used to achieve them are less obvious. In a Texas colony of Cattle Egrets (Bubulcus ibis), sibling aggression was frequent but siblicide rare. Parents rarely interfered with fights. Last-hatched chicks lost more fights and received less food than their elder siblings. Fighting limited the losers' immediate access to food and contributed to the senior sib's ability to monopolize boluses. These results are consistent with the hypothesis that monopolizable food can act as both a proximate and ultimate cause of sibling aggression. The main effect of sibling aggression lay in depressing food supplies to last-hatched chicks. First- and second-hatched sibs accrued roughly equal feeding advantages.

The importance of human resources to the innovative capacity of portuguese firms

2014 ◽  
Author(s):  
Armando Silva
Keyword(s):  
Human Resources ◽  
Innovation Process ◽  
Community Innovation Survey ◽  
Innovative Process ◽  
Qualified Personnel ◽  
Main Effect ◽  
Innovation Capacity ◽  
Innovative Capacity ◽  
Training Of Personnel

In this study I test the importance of several Human Resource variables to the innovation capacity of portuguese firms but also the effects that the innovation process generates on Human Resources. A branch of the innovation literature states that the ability of firms to innovate relies on an innovative capacity, which, in turn, depends on several factors, both internal and external to enterprises. One of those factors is the effort of firms to train their personnel specifically in order to enable them to innovate. The present test is applied to 4818 Portuguese enterprises for the period 2002-2004 through the use of the fourth Community Innovation Survey data. In order to evaluate the contribution of Human Resources to innovation I have estimated several knowledge Production Functions, mainly using probits and tobits. In that framework it is assumed that innovation depends on some inputs (as the training of personnel) and on information-flows from the existing knowledge stock (as clients). I have found significant the role of personnel training for the innovative process of Portuguese firms. Moreover, I also found that the lack of qualified personnel hinged critically more innovative performance of firms and, in addition, it is noticed that the improvement of productivuty (cost reduction) was the main effect of innovation in Portuguese firms.

scholarly journals Evaluation of the Effectiveness of Brazilian Community Restaurants for the Dimension of Low-Income People Access to Food

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2671
Author(s):  
Mateus Santana Sousa ◽  
Camila Silveira Silva Teixeira ◽  
Jamacy Costa Souza ◽  
Priscila Ribas de Farias Costa ◽  
Renata Puppin Zandonadi ◽  
...  
Keyword(s):  
Low Income ◽  
Formal Education ◽  
Average Energy ◽  
Secondary Data ◽  
Target Population ◽  
Service Capacity ◽  
The Public ◽  
The Government ◽  
Access To Food

This study aimed to evaluate the effectiveness of community restaurants (CRs), managed by the Government of the State of Bahia/Brazil, for the dimension of access to food. The study used secondary data obtained from the public opinion survey Profile of users of community restaurants in Salvador. The nutritional information was accessed through the analysis of CRs’ menus. Adequate effectiveness of access to food was considered when the CR served meals to 50% to 70% of the users considered the target audience (individuals served by the two CRs located in the city of Salvador/Bahia/Brazil). The participants (n = 1464; 778 as low-income individuals) were adult CR users from Salvador/Brazil. Most of the respondents were male, 40 to 54 years old, not white, had up to 9 years of formal education, without a partner, and living in the municipality of Salvador. The evaluated CRs are effective in serving 53.1% of the target population in their total service capacity. Meal provision only reached an estimated 0.7% of the socially vulnerable community in the district. The average energy value of the meal served by the CR units was 853.05 kcal/meal, with a mean energy density composition classified as average (1.15 kcal/g). The effectiveness of the evaluated community restaurants showed that these instruments were minimally effective in promoting access to food for the low-income population within their total daily service capacity, and the current quantity of these facilities was insufficient. However, these instruments stand out in the fundamental role of promoting the daily distribution of meals to the Brazilian population with the highest social vulnerability levels.

scholarly journals Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka
Keyword(s):  
Bird Species ◽  
Tropical Regions ◽  
Isthmus Of Panama ◽  
Species Pairs ◽  
The Matrix ◽  
High Species Richness ◽  
The Rich ◽  
The Tropics ◽  
The Impact

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

TOLERATED CO-FEEDING IN RELATION TO DEGREE OF KINSHIP IN JAPANESE MACAQUES

Behaviour ◽  
2001 ◽  
Vol 138 (4) ◽  
pp. 487-509 ◽  
Author(s):  
Bernard Chapais ◽  
Patrick Belisle
Keyword(s):  
Macaca Fuscata ◽  
Japanese Macaques ◽  
Preferential Treatment ◽  
Feeding Rates ◽  
Dominance Relationship ◽  
Mothers And Daughters ◽  
Dominant Female ◽  
Different Types ◽  
Access To Food

AbstractWe analyzed co-feeding in relation to degree of kinship in Japanese macaques Macaca fuscata), testing experimentally five categories of matrilineal kin dyads: mother-daughter, grandmother-granddaughter, sisters, aunt-niece and nonkin. In each test, two adult females with a clear dominance relationship had access to a box containing a limited quantity of highly prized food. The dominant female could easily prevent the subordinate from eating so that food was easily monopolizable, hence the use of the expression tolerated co-feeding. Rates of tolerated co-feeding increased steeply with degree of kinship. The aggression levels of dominant females towards subordinate females decreased with increasing degree of kinship and this effect was most apparent between mothers and daughters. The confidence level of subordinate females increased with degree of kinship and this effect became apparent above the aunt-niece kin class. Prior access to food by the subordinate female was a significant means of access to food, mostly beyond the grandmother-granddaughter kin category. The results point to a relatedness threshold for the preferential treatment of kin at r = 0.25 (grandmother-granddaughter and sister dyads), beyond which (r = 0.125: aunt-niece dyads), levels of tolerated co-feeding were comparable to those of nonkin females. The identity of this threshold with that found in previous studies on the same group for two different types of interactions suggests the existence of a generalized relatedness threshold for kin favoritism in Japanese macaques. Assuming that the costs of food defense by the dominant females were negligible and that tolerated co-feeding was altruistic, our results support the role of kin selection in the evolution of altruism in primates beyond the mother-offspring bond.

Judgments of truth are independently modulated by affect and repetition

2021 ◽  
Author(s):  
Patricia Garrido-Vásquez ◽  
Tanja Rock
Keyword(s):  
Negative Affect ◽  
Positive Affect ◽  
Theoretical Perspective ◽  
Processing Fluency ◽  
Neutral Picture ◽  
Truth Effect ◽  
New Information ◽  
Affective Processes ◽  
Main Effect

People believe repeated statements more than new ones—the repetition-induced truth effect. It is prominently explained with processing fluency: The subjective ease of processing repeated versus new information. To date, the role of affective processes for the truth effect is rather unclear. From a theoretical perspective, people should rely more on fluency under positive than under negative affect. Here, we tested whether an affective picture presented before a statement influences the repetition-induced truth effect. Thirty-five participants took part in two sessions that were a week apart. In both sessions, they rated the truth status of statements. In session 2, repeated and new statements were intermixed, and each statement was preceded by a positive, negative, or neutral picture. We expected participants to rely more on fluency as a cue to truth in the positive than in the negative affective condition. However, although we replicated the repetition-induced truth effect, the interaction between affect and repetition was insignificant, but we observed a significant main effect of affect—statements were rated as truer after a positive rather than a negative or neutral picture. Our results suggest two independent mechanisms that enhance the subjective truth of statements: repetition and positive affect.

The Role of Women in Improving Access to Food at the Household Level in Mandeni Local Municipality, KwaZulu-Natal, South Africa

2021 ◽  
Vol 10 (2) ◽  
pp. 135-155
Author(s):  
Nondumiso Thabisile Mpanza ◽  
Mfaniseni Wiseman Mbatha
Keyword(s):  
Food Security ◽  
Low Income ◽  
Home Gardens ◽  
Household Food Security ◽  
Exploratory Research ◽  
Structured Interviews ◽  
Household Level ◽  
Role Of Women ◽  
Access To Food

This paper censoriously assesses the role of women in improving access to food at the household level. The role of women is essential in the production of food as caretakers of household food security. However, their role is not well recognised, more especially in policymaking and resource allocation. This study was conducted through a qualitative approach with an exploratory research design. The participants were sampled with convenience sampling and interviewed with semi-structured interviews. Content analysis was employed as a tool for data analysis. The study adopted feminisation of poverty as a primary theory of this paper. Certain aspects of the study reveal that women have been struggling to access food from the diversity of retail vents that are obtainable in town because of low income and limitations of transport service. This is a constraint to women who depend on the off-farm sources of income because their household’s livelihood depends on purchasing food from retail vents. Those who rely on home gardens were experiencing low productivity and the unsustainability of their gardens. This has been caused by water scarcity and climate change. Therefore, women must be provided with training that seeks to develop their skills on how to make effective use of home gardens so that food security can be ensured.

scholarly journals Unraveling the functional role of DNA methylation using targeted DNA demethylation by steric blockage of DNA methyltransferase with CRISPR/dCas9

2020 ◽  
Author(s):  
Daniel M. Sapozhnikov ◽  
Moshe Szyf
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Promoter Region ◽  
Dna Methyltransferase ◽  
Dna Demethylation ◽  
New Method ◽  
Inducible Promoters ◽  
Specific Targeting ◽  
Main Effect

AbstractAlthough associations between DNA methylation and gene expression were established four decades ago, the causal role of DNA methylation in gene expression remains unresolved. Different strategies to address this question were developed; however, all are confounded and fail to disentangle cause and effect. We developed here a highly effective new method using only deltaCas9(dCas9):gRNA site-specific targeting to physically block DNA methylation at specific targets in the absence of a confounding flexibly-tethered enzymatic activity, enabling examination of the role of DNA methylation per se in living cells. We show that the extensive induction of gene expression achieved by TET/dCas9-based targeting vectors is confounded by DNA methylation-independent activities, inflating the role of DNA methylation in the promoter region. Using our new method, we show that in several inducible promoters, the main effect of DNA methylation is silencing basal promoter activity. Thus, the effect of demethylation of the promoter region in these genes is small, while induction of gene expression by different inducers is large and DNA methylation independent. In contrast, targeting demethylation to the pathologically silenced FMR1 gene targets robust induction of gene expression. We also found that standard CRISPR/Cas9 knockout generates a broad unmethylated region around the deletion, which might confound interpretation of CRISPR/Cas9 gene depletion studies. In summary, this new method could be used to reveal the true extent, nature, and diverse contribution to gene regulation of DNA methylation at different regions.

scholarly journals Great cormorant (Phalacrocorax carbo) predation on pikeperch (Sander lucioperca L.) in shallow eutrophic lakes in Poland

2017 ◽  
Vol 25 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Piotr Traczuk ◽  
Andrzej Kapusta
Keyword(s):  
Length Distribution ◽  
Bird Species ◽  
Fish Populations ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Sander Lucioperca ◽  
Eutrophic Lakes ◽  
Breeding Colony ◽  
Great Cormorants

AbstractIncreases in the population abundance of the piscivorous great cormorant (Phalacrocorax carbo) has led to conflicts with fisheries. Cormorants are blamed for decreased fish catches in many lakes in Poland. The aim of this paper is to describe to role of pikeperch (Sander lucioperca) in the diet of cormorants nesting in a colony on the island in Lake Warnołty. Since the breeding colony is located in the vicinity of Lake OEniardwy, the largest lake in Poland, the cormorants use the resources in this lake. In 2009-2016, 18,432 regurgitated fish were collected, of which 593 were pikeperch. The share of pikeperch among fish collected in 2009-2012 did not exceed 2%, but from 2013 this increased substantially to maximum of 38.2% in 2015. The smallest pikeperch had a standard length of 8.4 cm, and the largest 42.5 cm. Pikeperch mean length differed by year, and the length distribution was close to normal. The sizes of the regurgitated pikeperch indicate that cormorants prey almost exclusively on juvenile specimens. The results of the present study indicate that cormorant predation has a significant impact on pikeperch populations in lakes in the vicinity of the colony, and the great cormorants are possibly a significant factor in the effectiveness of pikeperch management. When planning for the management of fish populations in lakes subjected to cormorant predation pressure, it should be borne in mind that predation by this piscivorous bird species impacts the abundance and size-age structure of fish populations.

scholarly journals Impact of Manganese on Pollen Germination and Tube Growth in Lily

2021 ◽  
Vol 74 ◽  
Author(s):  
Thomas Sawidis ◽  
Gülriz Baycu ◽  
Elżbieta Weryszko-Chmielewska ◽  
Aneta Sulborska
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Surrounding Medium ◽  
Pollen Grains ◽  
Lilium Longiflorum ◽  
Tube Growth ◽  
Low Concentrations ◽  
Main Effect

Abstract In vitro culture of Lilium longiflorum pollen grains was carried out to determine the role of manganese in pollen germination and pollen tube growth. Pollen germination was adversely affected by the presence of manganese (>10 −8 M), whereas low concentrations (10 −12 –10 −10 M) stimulated the process. Manganese caused morphological anomalies during tube growth, characterized by irregular pollen tube thickening and swollen tips. The main effect was the anomalous cell wall formation at the tip, in which the presence of several organelles reduced the number of secretory vesicles. A loose network of fibrillar material and spherical aggregates, mostly in the tip region, was detected, and this material was progressively loosened into the surrounding medium. As a response to potential toxicity, the excess manganese was isolated in vacuoles, which formed an internal barrier against penetration of manganese to the tip area. Elevated manganese concentrations might affect plant reproduction, resulting in anomalies in gamete development. Consequently, the loss in genetic diversity and decreased fruit set ultimately lower yield.

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