Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Dois novos complexos zwitteriônicos de oxorrênio(V), [ReOCl2(Hdhp)(PPh3)] (1) e [ReOBr2(Hdhp)(PPh3)] (2) (H2dhp = 2,3-dihidroxipiridina), foram sintetizados e caracterizados por espectroscopia de absorção no infravermelho, ressonância magnética nuclear de ¹H e 31P, análise elementar e determinação da estrutura cristalina e molecular por difração de raios X em monocristais. Os complexos apresentam geometria de coordenação octaédrica bastante distorcida, com os dois ligantes haletos arranjados em posições cis equatoriais, o ligante trifenilfosfina em posição trans a um dos haletos e o ligante Hdhp- coordenado de forma bidentada através de seus átomos de oxigênio, sendo um em posição trans ao ligante oxo e o outro em posição trans com relação ao outro haleto. Este ligante tem seu átomo de nitrogênio protonado. Os compostos 1 e 2 apresentam empacotamento cristalino bastante diferente, influenciado em ambos os casos por ligações de hidrogênio intermoleculares dos tipos N-H...X (X = Cl, Br) e N-H...O.Two novel zwitterionic oxorhenium(V) complexes, [ReOCl2(Hdhp)(PPh3)] (1) and [ReOBr2(Hdhp)(PPh3)] (2) (H2dhp = 2,3-dihydroxypyridine), were synthesized and characterized by infrared spectroscopy, ¹H and 31P nuclear magnetic resonance, elemental analysis and crystal and molecular structure determination by X-ray diffraction on single crystals. Both complexes show distorted octahedral coordination geometry, with the halide ligands arranged in equatorial cis positions, the triphenylphosphine ligand in a trans position to one of the halides and the Hdhp- ligand coordinated in a bidentate form through its oxygen atoms, one in trans position to the oxo-ligand and the other in trans position to the second halide. The nitrogen atom of this ligand is protonated. Compounds 1 and 2 show quite different crystal packing, both influenced by hydrogen bonds of the types N-H...X (X = Cl, Br) and N-H...O

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Rhenium and technetium chelate-complexes of potential medicinal application

Neste trabalho foram estudadas as formas de coordenação de piridinonas, ditiocarbazatos e N-(N\'\',N\'\'-dialquilaminotiocarbonil)-N\'-(2-hidroxifenil)benzoamidinas aos centros metálicos Re (V) e Tc (V). Neste sentido, os complexos triclorobis(trifenilfosfina)oxorrênio(V), [ReOCl3(PPh3)2]57, tribromobis(trifenilfosfina)oxorrênio(V), [ReOBr3(PPh3)2]57, e tetraclorooxorenato(V) de tetrabutilamônio, (NBu4)[ReOCl4]58, foram sintetizados e utilizados como precursores. O precursor tetraclorooxotecnetato(V) de tetrabutilamônio, (NBu4)[TcOCl4], foi sintetizado e disponibilizado pelo grupo de Prof. Dr. Ulrich Abram, da Universidade Livre de Berlin, durante o período de trabalho realizado na Alemanha. Foram utilizadas as seguintes técnicas para a caracterização dos complexos sintetizados: espectroscopia de absorção na região do infravermelho, análise elementar (C, H, N e S), espectroscopia de ressonância magnética nuclear (31P, 1H e no caso de um dos complexos, também 13C), espectrometria de massas (MS-ESI) e determinação de estruturas cristalinas e moleculares, quando possível, por difração de raios X em monocristal. Por se tratar de um elemento radioativo, a avaliação do percentual de tecnécio em seus complexos foi determinada por meio da técnica de cintilação líquida. Deste o início deste trabalho foram sintetizados e caracterizados por diversas técnicas 14 novos complexos de rênio e 1 de tecnécio, todos inéditos. Seis ditiocarbazatos, sendo 5 inéditos, também foram sintetizados e caracterizados.This work evaluated the coordination mode of pyridinones, dithiocarbazates and N-(N\'\',N\'\'-Diethylaminothiocarbonyl)-N\'-(2-hydroxyphenyl)benzamidine, to the metal centers Re (V) and Tc (V). For this purpose, the compounds trichlorobis(triphenylphosphine)oxorhenium(V), [ReOCl3(PPh3)2]43, tribromobis(triphenylphosphine)oxorhenium(V), [ReOBr3(PPh3)2]43, and tetra-n-butyl)ammonium tetrachlorooxorhenate(V), (NBu4)[ReOCl4]44, were synthesized and used as starting materials. The precursor tetra-n-butylammonium tetrachlorooxotechnetate(V), (NBu4)[TcOCl4] was synthesized and released by the Prof. Dr. Ulrich Abram\'s group, at the Freie Universität Berlin, during my research time in Germany. The complexes were characterized by infrared absorption spectroscopy, elemental analyses (CHNS), mass spectrometry with electrospray ionization (MSESI), nuclear magnetic resonance spectroscopy (31P, 1H and, in one case, also 13C) and had their crystalline and molecular structures, when possible, properties determined by X-ray diffraction on single crystals. Due to its radioactive element, the 99Tc values were determined by standard liquid scintillation counting. Since the beginning of this work were synthesized and characterized by various techniques 14 new rhenium and 1 technetium complexes, all of then unknown in the literature. All the complexes presented here were obtained in good or excellent yields. Six new dithiocarbazates were obtained and characterized, of which 5 are unknown

Ano IX, número 19

Espaço e Economia: Revista Brasileira de Geografia Econômica, além dos artigos em fluxo contínuo, inclui nesta edição o Dossiê Oeste Metropolitano do Rio de Janeiro, organizado pelos professores Marcio Rufino Silva, Denise de Alcantara, Leandro Dias de Oliveira e André Santos da Rocha (PPGGEO e PPGDT-UFRRJ)