Strengthening measurements from the edges: application-level packet loss rate estimation

Network users know much less than ISPs, Internet exchanges and content providers about what happens inside the network. Consequently users cannot either easily detect network neutrality violations or readily exercise their market power by knowledgeably switching ISPs. This paper contributes to the ongoing efforts to empower users by proposing two models to estimate -- via application-level measurements -- a key network indicator, i.e., the packet loss rate (PLR) experienced by FTP-like TCP downloads. Controlled, testbed, and large-scale experiments show that the Inverse Mathis model is simpler and more consistent across the whole PLR range, but less accurate than the more advanced Likely Rexmit model for landline connections and moderate PL

2-(Phenyl­carbonothio­ylsulfan­yl)acetic acid

The title compound, C9H8O2S2, can be used as a chain transfer agent and may be used to control the behavior of polymerization reactions. O—H⋯O hydrogen bonds of moderate character link the mol­ecules into dimers. In the crystal, the dimers are linked into sheets by C—H⋯O inter­actions, forming R 4 2(12) and R 2 2(8) edge-fused rings running parallel to [101]. There are no inter­molecular inter­actions involving the S atoms

3-(2,4-Dibromo­anilino)-2,2-dimethyl-2,3-dihydro­naphtho[1,2-b]furan-4,5-dione: a new substituted aryl­amino nor-β-lapachone derivative

The title compound, C20H15Br2NO3, shows the furan ring to adopt a half-chair conformation and the two ring systems to be approximately perpendicular [dihedral angle = 71.0 (2)°]. In the crystal structure, inter­molecular C—H⋯O contacts link the mol­ecules

Trait interactions effects on tropical tree demography depend on the environmental context

Although functional traits are defined based on their impact on demographic parameters, trait-demography relationships are often reported as weak. These weak relationships might be due to disregarding trait interactions and environmental contexts, which should modulate species trait-demography relationships. We applied different models, including boosted regression tree (BRT) models, to investigate changes in the relationship between traits and demographic rates of tropical tree species in plots along an elevational gradient and among time intervals between censuses, analyzing the effect of a strong drought event. Based on a large dataset of 18,000 tree individuals from 133 common species, distributed among twelve 1-ha plots (habitats) in the Atlantic Forest (Brazil), we evaluated how trait interactions and the environmental context influence the demographic rates (growth, mortality, and recruitment). Functional traits, trait-trait, and trait-habitat interactions predicted demography with a good fit through either BRTs or linear mixed-models. Changes in growth rates were best related to size (diameter), and mortality rates to habitats, while changes in recruitment rates were best related to the specific leaf area. Moreover, the influence of traits differed among time intervals, and for demographic parameters, habitat affected growth and mortality by interacting with diameter. Here, we provide evidence that trait-demography relationships can be improved when considering the environmental context (space and time) and trait interactions to cope with the complexity of changes in the demography of tropical tree communities. Thus, to expand predictions of demography based on functional traits, we show that it is useful to fully incorporate the concept of multiple trait-fitness optima, resulting from trait interactions in different habitats and growth conditions.We thank the Brazilian National Research Council (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for the scholarships conceded to the first author (CNPq 141781/2016-5 and CAPES 88881.189491/2018-01) and for the productivity fellowship to FAMS (CNPq 310168/2018-0). This study was financed by research funding of the projects: “Functional Gradient” (Biota/FAPESP 03/12595-7), “PELD/BIOTA” and “ECOFOR” (Processes 2012/51509-8 and 2012/51872-5, within the BIOTA/FAPESP Program), “EcoSpace” (Edital Universal CNPq 459941/2014-3), “Sustainable Landscapes Brazil” project (US Forest Service, USAID, US Department of State and EMBRAPA), and “Sustainable Landscapes” (NASA-Goddard). This study was also supported by CNPq (PELD CNPq 403710/2012-0), British Natural Environment Research Council/NERC (NE/K016431/1) and FAPESP as part of a doctoral fellowship (FAPESP 11/11604-0). CPC was financed by the Estonian Research Council (PSG293)

4-Methyl­phenyl 4-bromo­benzoate

In the title compound, C14H11BrO2, an ester formed from the reaction of 4-methyl­phenol with 4-bromo­benzoyl­chloride, the dihedral angle between the benzene rings is 54.43 (7)°, indicating a twist in the mol­ecule. In the crystal, weak C—H⋯O inter­actions link the mol­ecules into supra­molecular layers in the bc plane, and these are connected along the a axis by Br⋯Br contacts [3.6328 (5) Å]

trans-5,6-Diphenyl­perhydro­pyran-2,4-dione

In the title compound, C17H14O3, the pyran ring adopts a boat conformation and the dihedral angle between the aromatic ring planes is 59.1 (1)°. In the crystal structure inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions link the mol­ecules

1-(4-Bromo­phen­yl)-2-ethyl­sulfinyl-2-(phenyl­selan­yl)ethanone monohydrate

In the title hydrate, C16H15BrO2SSe·H2O, the sulfinyl O atom lies on the opposite side of the mol­ecule to the Se and carbonyl O atoms. The benzene rings form a dihedral angle of 51.66 (17)° and are splayed with respect to each other. The observed conformation allows the water mol­ecules to bridge sulfinyl O atoms via O—H⋯O hydrogen bonds, generating a linear supra­molecular chain along the b axis; the chain is further stabilized by C—H⋯O contacts. The chains are held in place in the crystal structure by C⋯H⋯π and C—Br⋯π inter­actions

2-(4-Methyl­phen­yl)-1H-anthraceno[1,2-d]imidazole-6,11-dione: a fluorescent chemosensor

In the title compound, C22H14N2O2, the five rings of the mol­ecule are not coplanar. There is a significant twist between the four fused rings, which have a slightly arched conformation, and the pendant aromatic ring, as seen in the dihedral angle of 13.16 (8)° between the anthraquinonic ring system and the pendant aromatic ring plane

cis-Bis[1,1-dibenzyl-3-(furan-2-yl­carbonyl)thio­ureato-κ2 O,S]copper(II)

In the title compound, [Cu(C20H17N2O2S)2], the CuII atom is coordinated by the S and O atoms of two 1,1-dibenzyl-3-(furan-2-ylcarbon­yl)thio­ureate ligands in a distorted square-planar geometry. The two O and two S atoms are mutually cis to each other. The Cu—S and Cu—O bond lengths lie within the ranges of those found in related structures. The dihedral angle between the planes of the two chelating rings is 26.15 (6)°