Division of labour and risk taking in the dinosaur ant, Dinoponera quadriceps

The success of social insects can be largely attributed to division of labour. In contrast to most social insects, many species with simple societies contain workers which are capable of sexual reproduction. Headed by one or a few reproductive individuals, subordinate workers form a dominance hierarchy, queuing to attain the reproductive role. In these species task allocation may be influenced by individual choice based on future reproductive prospects. Individuals with a better chance of inheriting the colony may be less likely to take risks and high-ranking workers that spend a greater amount of time in proximity to the brood may be able to increase the ability to police egg-laying by cheating subordinates. We investigated division of labour and risk taking in relation to dominance rank in the queenless ponerine ant, Dinoponera quadriceps, a species with relatively simple societies. Using behavioural observations, we show that high-ranking workers spend more time performing egg care, less time foraging and are less likely to defend the nest against attack. High-rankers also spent a greater amount of time guarding and inspecting eggs, behaviours which are likely to improve detection of egg laying by cheating subordinates. We also show that high-ranking workers spend a greater amount of time idle, which may help increase lifespan by reducing energy expenditure. Our results suggest that both risk-taking and egg-care behaviours are related to future reproductive prospects in D. quadriceps. This highlights a mechanism by which effective division of labour could have been achieved during the early stages of eusocial evolution

“Empty spaces ‘Where’ we are living for” – First record of Dinoponera quadriceps reusing nests of Atta sexdens

The reuse of nests by the same or different species can save a colony energy and resources. Furthermore, it can increase colony growth and the production of brood. The queenless ant Dinoponera quadriceps builds deep nests in Caatinga to escape from the dry and hot environment. The reuse of deep nests from other species can provide D. quadriceps with protection from high temperature, whilst saving on the energy required to build new nests. Here, we present the first finding of D. quadriceps reusing the nest of Atta sexdens species

“Empty spaces ‘Where’ we are living for” – First record of Dinoponera quadriceps reusing nests of Atta sexdens

The reuse of nests by the same or different species can save a colony energy and resources. Furthermore, it can increase colony growth and the production of brood. The queenless ant Dinoponera quadriceps builds deep nests in Caatinga to escape from the dry and hot environment. The reuse of deep nests from other species can provide D. quadriceps with protection from high temperature, whilst saving on the energy required to build new nests. Here, we present the first finding of D. quadriceps reusing the nest of Atta sexdens species

Appetite for self-destruction: suicidal biting as a nest defense strategy in Trigona stingless bees

Self-sacrificial behavior represents an extreme and relatively uncommon form of altruism in worker insects. It can occur, however, when inclusive fitness benefits are high, such as when defending the nest. We studied nest defense behaviors in stingless bees, which live in eusocial colonies subject to predation. We introduced a target flag to nest entrances to elicit defensive responses and quantified four measures of defensivity in 12 stingless bee species in São Paulo State, Brazil. These included three Trigona species, which are locally known for their aggression. Species varied significantly in their attack probability (cross species range = 0–1, P < 0.001), attack latency (7.0–23.5 s, P = 0.002), biting duration of individual bees (3.5–508.7 s, P < 0.001), and number of attackers (1.0–10.8, P < 0.001). A “suicide” bioassay on the six most aggressive species determined the proportion of workers willing to suffer fatal damage rather than disengage from an intruder. All six species had at least some suicidal individuals (7–83 %, P < 0.001), reaching 83 % in Trigona hyalinata. Biting pain was positively correlated with an index of overall aggression (P = 0.002). Microscopic examination revealed that all three Trigona species had five sharp teeth per mandible, a possible defensive adaptation and cause of increased pain. Suicidal defense via biting is a new example of self-sacrificial altruism and has both parallels and differences with other self-sacrificial worker insects, such as the honey bee. Our results indicate that suicidal biting may be a widespread defense strategy in stingless bees, but it is not universal

O estudo da Agroecologia como disciplina dentro dos cursos tradicionais de Engenharia Agronômica

O presente trabalho pretende entender as dificuldades em ministrar a Agroecologia como disciplina dentro de cursos tradicionais de Engenharia Agronômica. Como objetivo pretendido neste estudo está a caracterização de como a Agroecologia é vista dentro de um currículo tradicionais pelos acadêmicos, como ela é trabalhada pelo professor dentro desta ótica tradicional de agricultura voltada ao agronegócio e as dificuldades encontradas em trabalhar a disciplina dentro de uma visão curricular ainda tradicional. Este trabalho tem como importância entender como seria a melhor forma de trabalhar a disciplina dentro de um modelo tradicional de Engenharia Agronômica. A metodologia usada foi o estudo de caso da disciplina de Agroecologia do Instituto Federal do Paraná (IFPR) do curso de Engenharia Agronômica do Campus Palmas (PR) ministrada para duas turmas. Conclui-se que os alunos tem uma ideia equivocada do que é Agroecologia e muitas dúvidas sobre o assunto e muitos deles não creem que seja possível se ter uma agricultura que tenha como pilares a Agroecologia.This work intends to understand the difficulties of ministering to Agroecology as a discipline within traditional courses of Agricultural Engineering. As intended goal in this study is the characterization of how Agroecology is seen within a traditional curriculum for academic, as it is worked by the teacher under this perception of traditional agriculture and agribusiness focused on the difficulties encountered in working discipline within a curricular vision yet traditional. This work is important to understand how would be the best way of working discipline within a traditional model of Agronomy. The methodology used was the case study of Agroecology discipline of the Federal Institute of Paraná (IFPR) the course of the Agronomic Engineering Campus Palmas (PR) given to two groups. It was concluded that students have a mistaken idea of what Agroecology and many questions about it and many of them do not believe it is possible to have an agriculture that has as pillars Agroecology.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale

O estudo da Agroecologia como disciplina dentro dos cursos tradicionais de Engenharia Agronômica

O presente trabalho pretende entender as dificuldades em ministrar a Agroecologia como disciplina dentro de cursos tradicionais de Engenharia Agronômica. Como objetivo pretendido neste estudo está a caracterização de como a Agroecologia é vista dentro de um currículo tradicionais pelos acadêmicos, como ela é trabalhada pelo professor dentro desta ótica tradicional de agricultura voltada ao agronegócio e as dificuldades encontradas em trabalhar a disciplina dentro de uma visão curricular ainda tradicional. Este trabalho tem como importância entender como seria a melhor forma de trabalhar a disciplina dentro de um modelo tradicional de Engenharia Agronômica. A metodologia usada foi o estudo de caso da disciplina de Agroecologia do Instituto Federal do Paraná (IFPR) do curso de Engenharia Agronômica do Campus Palmas (PR) ministrada para duas turmas. Conclui-se que os alunos tem uma ideia equivocada do que é Agroecologia e muitas dúvidas sobre o assunto e muitos deles não creem que seja possível se ter uma agricultura que tenha como pilares a Agroecologia.This work intends to understand the difficulties of ministering to Agroecology as a discipline within traditional courses of Agricultural Engineering. As intended goal in this study is the characterization of how Agroecology is seen within a traditional curriculum for academic, as it is worked by the teacher under this perception of traditional agriculture and agribusiness focused on the difficulties encountered in working discipline within a curricular vision yet traditional. This work is important to understand how would be the best way of working discipline within a traditional model of Agronomy. The methodology used was the case study of Agroecology discipline of the Federal Institute of Paraná (IFPR) the course of the Agronomic Engineering Campus Palmas (PR) given to two groups. It was concluded that students have a mistaken idea of what Agroecology and many questions about it and many of them do not believe it is possible to have an agriculture that has as pillars Agroecology.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale

Bradykinin Release Avoids High Molecular Weight Kininogen Endocytosis

Human H-kininogen (120 kDa) plays a role in many pathophysiological processes and interacts with the cell surface through protein receptors and proteoglycans, which mediate H-kininogen endocytosis. in the present work we demonstrate that H-kininogen containing bradykinin domain is internalized and different endogenous kininogenases are present in CHO-K1 cells. We used CHO-K1 (wild type) and CHO-745 (mutant deficient in proteoglycans biosynthesis) cell lines. H-kininogen endocytosis was studied using confocal microscopy, and its hydrolysis by cell lysate fraction was determined by immunoblotting. Bradykinin release was also measured by radioimmunoassay. H-kininogen interaction with the cell surface of CHO-745 cells resulted in bradykinin release by serine proteases. in CHO-K1 cells, which produce heparan and chondroitin sulfate proteoglycans, internalization of H-kininogen through its bradykinin domain can occur on lipid raft domains/caveolae. Nevertheless bradykinin-free H-kininogen was not internalized by CHO-K1 cells. the H-kininogen present in acidic endosomal vesicles in CHO-K1 was approximately 10-fold higher than the levels in CHO-745. CHO-K1 lysate fractions were assayed at pH 5.5 and intact H-kininogen was totally hydrolyzed into a 62 kDa fragment. By contrast, at an assay pH 7.4, the remained fragments were 115 kDa, 83 kDa, 62 kDa and 48 kDa in size. the anti-pain-Sepharose chromatography separated endogenous kininogenases from CHO-K1 lysate fraction. No difference was detected in the assays at pH 5.5 or 7.4, but the proteins in the fraction bound to the resin released bradykinin from H-kininogen. However, the proteins in the unbound fraction cleaved intact H-kininogen at other sites but did not release bradykinin. H-kininogen can interact with extravascular cells, and is internalized dependent on its bradykinin domain and cell surface proteoglycans. After internalization, H-kininogen is proteolytically processed by intracellular kininogenases. the present data also demonstrates that serine or cysteine proteases in lipid raft domains/caveolae on the CHO cell can hydrolyze H-kininogen, thus releasing kinins.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao de Apoio a Universidade Federal de São Paulo-FAP/UNIFESPUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Bioquim, São Paulo, SP, BrazilUniv Anhanguera São Paulo UNIAN SP, Programa Biomat, São Paulo, SP, BrazilUniv Anhanguera São Paulo UNIAN SP, Programa Biotecnol, São Paulo, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Biofis, São Paulo, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Bioquim, São Paulo, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Biofis, São Paulo, SP, BrazilCNPq: CNPq 472403/2007-9FAPESP: FAPESP 13/05822-9FAPESP: FAPESP 2012/50219-6Web of Scienc

Lipases and lipid droplet-associated protein expression in subcutaneous white adipose tissue of cachectic patients with cancer

Background: Cancer cachexia is a multifactorial metabolic syndrome characterized by marked loss of adipose tissue and skeletal muscle. Fat loss from adipose tissue in cancer cachexia is partly the result of increased lipolysis. Despite the growing amount of studies focused on elucidating the mechanisms through which lipolysis-related proteins regulate the lipolytic process, there are scarce data concerning that profile in the adipose tissue of cancer cachectic patients. Considering its fundamental importance, it was our main purpose to characterize the expression of the lipolysis-related proteins in the white adipose tissue of cachectic cancer patients. Methods: Patients from the University Hospital were divided into three groups: control, cancer cachexia (CC), and weight-stable cancer patients (WSC). To gain greater insight into adipose tissue wasting during cancer cachexia progression, we have also analyzed an experimental model of cachexia (Walker 256 carcinosarcoma). Animals were divided into: control, intermediate cachexia (IC) and terminal cachexia (TC). Subcutaneous white adipose tissue of patients and epidydimal white adipose tissue of animals were investigated regarding molecular aspects by determining the protein content and gene expression of hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL), comparative gene identification-58 (CGI-58), perilipin 1, leptin, adiponectin, visfatin, and tumour necrosis factor alpha (TNF-alpha). Results: We found augmented lipolysis in CC associated with increased HSL expression, as well as upregulation of ATGL expression and reduction in perilipin 1 content. In IC, there was an imbalance in the secretion of pro-and anti-inflammatory factors. The alterations at the end-stage of cachexia were even more profound, and there was a reduction in the expression of almost all proteins analyzed in the animals. Conclusions: Our findings show that cachexia induces important morphological, molecular, and humoral alterations in the white adipose tissue, which are specific to the stage of the syndrome.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Canc Metab Res Grp, Inst Biomed Sci, Dept Surg,Fac Med, São Paulo, BrazilSão Paulo State Univ UNESP, Exercise & Immunometab Res Grp, Dept Phys Educ, Presidente Prudente, SP, BrazilUniv Fed São Paulo, UNIFESP, Dept Fisiol, São Paulo, BrazilUniv São Paulo, Univ Hosp, Dept Clin Surg, São Paulo, BrazilUniv Mogi das Cruzes, Lab Adipose Tissue Biol, Ctr Integrated Biotechnol, Mogi Das Cruzes, BrazilUniv São Paulo, Inst Biomed Sci, Ave Prof Lineu Prestes 1524,Lab 434, BR-05508900 São Paulo, SP, BrazilUniv Fed São Paulo, UNIFESP, Dept Fisiol, São Paulo, BrazilFAPESP: 2012/50079-0Web of Scienc

Bourgeois behavior and freeloading in the colonial orb web spider Parawixia bistriata (Araneae, Araneidae)

Spiders of the tropical American colonial orb weaver Parawixia bistriata form a communal bivouac in daytime. At sunset, they leave the bivouac and construct individual, defended webs within a large, communally built scaffolding of permanent, thick silk lines between trees and bushes. Once spiders started building a web, they repelled other spiders walking on nearby scaffolding with a "bounce" behavior. In nearly all cases (93%), this resulted in the intruder leaving without a fight, akin to the "bourgeois strategy," in which residents win and intruders retreat without escalated contests. However, a few spiders (6.5%) did not build a web due to lack of available space. Webless spiders were less likely to leave when bounced (only 42% left) and instead attempted to "freeload," awaiting the capture of prey items in nearby webs. Our simple model shows that webless spiders should change their strategy from bourgeois to freeloading satellite as potential web sites become increasingly occupied