A Failure of Serendipity: the Square Kilometre Array will struggle to eavesdrop on Human-like ETI

The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if Extraterrestrial Intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth "radio quiet". If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo Realisation techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilisations are "human" in nature (i.e. they are only "radio loud" for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilisations accidentally detecting each other is low (~10^{-7}), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication).Comment: 8 pages, 2 figures, accepted for publication in the International Journal of Astrobiolog

Estimation of morphoestructural traits in moxoto breed goats

The raising goat systems in Brazil are characterized as extensive or semi-extensive in the majority of them. In native breeds dominate the extensive system, being common introduction of exotic breed as Anglo Nubian and Boer. In addition, the geographic isolation difficulty change of sires, promote genetic isolation and changes in breed pattern, consequently. The objective of the present work were to evaluate eleven quantitative morphoestructural traits: raised to the withers (RW), raised to the entrance of croup (RC), thoracic perimeter (PT), width of croup (WC), length of croup (LC), width of head (WH), face length (FL), width of face (WF), ear size (ES), shin circumference of the cinnamon (CCi) of 313 Moxoto animal breed of several municipality of Pernambuco and Paraíba States, northeastern, semi arid region of Brazil. According to canonical analyses it is possible to verify diferentiation and sub populations formation.Os sistemas de produção de caprinos no Brasil caracterizam-se na sua maioria como extensivo ou semi-extensivo. Porém, na criação de caprinos nativos predomina o sistema ultra-extensivo, sendo comum a introdução de animais exóticos, principalmente das raças Anglo Nubiana e Boer para cruzamento com o rebanho local, fato que tem contribuído para diluição genética e perda das características raciais.. Além disso, o isolamento geográfico a que estão submetidos, dificulta a troca de reprodutores entre rebanhos, promove isolamento genético e como conseqüência final, mudanças no padrão racial. O presente trabalho teve como objetivo utilizar onze variáveis morfo-estruturais de natureza quantitativas, tais como: longitude da cabeça (LC); longitude do rosto (LR); largura da cabeça (LCa); comprimento do corpo (CC); perímetro torácico (PT); altura da cernelha (AC); altura da região sacral (ARS); largura da garupa (LG); longitude da garupa (LGa); perímetro da canela (PCa) e; tamanho da orelha (TO) de 313 animais da raça caprina Moxotó, de diferentes municípios dos Estados de Pernambuco e Paraíba, região semi-árida do Nordeste brasileiro. Pela análise canônica foi possível verificar diferenciação e formação de sub-populações dentro da raça

Application of pineapple fiber in the development of sustainable mortars

Received: January 27th, 2021 ; Accepted: May 12th, 2021 ; Published: October 5th, 2021 ; Correspondence: [email protected] to the great worldwide increase in pineapple production, countries like Brazil and India have problems regarding the correct disposal of residues from the production of this fruit. One of the possibilities is the reuse of these residues in the form of fibers in cementitious materials, as is the case with mortars. As a result, the objective of this work is to evaluate the application of pineapple fibers in mortars in the proportion of 1: 4 (cement: sand) with addition of fiber treated in NaOH in the proportion of 3 and 6%. The properties of mechanical resistance, water absorption, mass density and adhesion were evaluated, aiming to apply the mortar in coatings of rural environments. The results indicate that the fibers reduced the mortar density and increased the mechanical strength. However, there was a reduction in adherence, especially with the use of 6% fiber, in addition to an increase in water absorption. Based on the results, it is concluded that it is feasible to use 3% of pineapple fiber for the production of coating mortars in rural environments because the results obtained in the investigation are compatible with this application and with the established normative limits

Adequação de uma cidade à smart city com a implementação de um fablab – uma fabcity

Estima-se que mais de 50% da população mundial vive em áreas urbanas e a projeção é que até o ano de 2030 esse número ultrapasse a casa dos 60%. Outro dado interessante é que cerca de metade da população mundial reside nas chamadas cidades de médio porte (aquelas com até 500 mil habitantes), e muitas das cidades que apresentam esse crescimento urbano são estes estabelecimentos urbanos menores. Essas cidades enfrentarão grandes desafios já que é previsto que 95% desse crescimento urbano programado aconteça nelas. Devido ao crescimento das cidades, torna-se cada vez maior a demanda por soluções para problemas mais críticos da sociedade devido à falta de planejamento urbano e recursos cada vez mais escassos e para resolução desses problemas sociais, o conceito de Smart city está sendo disseminado pelo mundo com o objetivo de propor soluções inteligentes para as diversas áreas como: saúde, educação e segurança. Ao contrario do que muitos acreditam, estudos recentes apontam que uma cidade só se torna inteligente quando a relação entre governança e seus habitantes tornam-se mais estreitas, promovendo uma troca de conhecimento de parte a parte. O objetivo do presente trabalho é a elaboração de um documento elencando os procedimentos necessários primeiramente para a criação de um FabLab aberto ao público para que as pessoas tenham um lugar para acolher, desenvolver e prototipar suas ideias com o intuito de melhorar a sociedade em que vivem e posteriormente fazer com que a cidade se torne uma cidade inteligente utilizando o FabLab como seu principal meio de desenvolvimentos de ideias que beneficiem de maneira imediata a vida das pessoas (FabCity).info:eu-repo/semantics/publishedVersio

Fibrinogen as independent risk factor for ischemic stroke

We have studied fibrinogen levels (Clauss technique) in atherothrombotic ischemic stroke patients, in order to determine its role as a thombogenic risk factor. Twenty nine patients (20 men and 9 women) between 25 and 79 years old were studied; they all have had a atherothrombotic stroke. They were classified into two groups according to the result of their carotid doppler ultrasonography: g1 - without carotid flow reduction (n=l 9) and g2 - with carotid flow reduction (n=10). The fibrinogen mean value was 269mg/dl in gl and 353 mg/dl in g2. There were 47% of patients in gl and 80% of patients in g2 who presented levels >300 mg/dl. The proportions of the groups were significantly different (p300 mg/dl. As diferenças obtidas entre os grupos neste estudo foram significantes. Conclusão- Considerando o nível de risco epidemiológico de 300 mg/dl, nossos resultados sugerem que o fibrinogênio é um fator de risco independente para AVC aterotrombótico, especialmente naqueles com alteração de fluxo carotídeo.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP, EPM, Depto. de MedicinaSciEL

Higher dimensional inhomogeneous dust collapse and cosmic censorship

We investigate the occurrence and nature of a naked singularity in the gravitational collapse of an inhomogeneous dust cloud described by higher dimensional Tolman-Bondi space-times. The naked singularities are found to be gravitationally strong in the sense of Tipler. Higher dimensions seem to favour black holes rather than naked singularities.Comment: 15 pages, LaTeX, 1 figure, 2 table

Recharge assessment in the context of expanding agricultural activity: Urucuia Aquifer System, western State of Bahia, Brazil

Groundwater recharge rate estimation is crucial to sustainable development of aquifers in intensely pumped regions, such as the Urucuia Aquifer System (UAS). A sedimentary aquifer in Western Bahia, Brazil, that underlies one of the major agricultural areas of the country where there has been major growth of irrigated areas. This study seeks to evaluate the recharge component of the water budget in the UAS area, based on three complementary techniques. The double-ring infiltrometer test was used to evaluate surface infiltration capacity, an important control on recharge. Water level data from wells (2011–2019 period, 19 wells) in the Brazilian Geological Survey’s Integrated Groundwater Monitoring Network (RIMAS-CPRM) was used to estimate the aquifer recharge using the water table fluctuation (WTF) method. Additionally, this study used the Soil Water Assessment Tool (SWAT) model in two selected sub-basins to estimate deep recharge from the surface hydrological data. The results of the infiltrometer tests show a notable difference in the infiltration rates between the natural vegetation zones and cropped areas. The WTF and SWAT simulations results suggest similar ranges of recharge rate (an average of 24% of precipitation, in both methods). Results of the study indicate equivalence of these methods to estimate the recharge in sedimentary unconfined aquifers as UAS

Trojan-like internalization of anatase titanium dioxide nanoparticles by human osteoblast cells

Dentistry and orthopedics are undergoing a revolution in order to provide more reliable, comfortable and long-lasting implants to patients. Titanium (Ti) and titanium alloys have been used in dental implants and total hip arthroplasty due to their excellent biocompatibility. However, Ti-based implants in human body suffer surface degradation (corrosion and wear) resulting in the release of metallic ions and solid wear debris (mainly titanium dioxide) leading to peri-implant inflammatory reactions. Unfortunately, our current understanding of the biological interactions with titanium dioxide nanoparticles is still very limited. Taking this into consideration, this study focuses on the internalization of titanium dioxide nanoparticles on primary bone cells, exploring the events occurring at the nano-bio interface. For the first time, we report the selective binding of calcium (Ca), phosphorous (P) and proteins from cell culture medium to anatase nanoparticles that are extremely important for nanoparticle internalization and bone cells survival. In the intricate biological environment, anatase nanoparticles form bio-complexes (mixture of proteins and ions) which act as a kind of ‘Trojan-horse’ internalization by cells. Furthermore, anatase nanoparticles-induced modifications on cell behavior (viability and internalization) could be understand in detail. The results presented in this report can inspire new strategies for the use of titanium dioxide nanoparticles in several regeneration therapies