catena-[1,3-diammoniopropane di-mu2-hydroxodi-mu4-phosphato-trioxotrivanadium dihydrate]: a redetermination at 180 (2) K

The crystal structure of the title compound, (C3H12N2)- [V3O3(OH)2(PO4)2] 2H2O, has been reported by Soghomonian et al. [Chem. Mater. (1993), 5, 1690±1691]. We present here a redetermination of greatly improved precision and at a low temperature of 180 (2) K. The H atoms connected to oxygen have been successfully located and the coordination environments of the two crystallographically independent vanadium centres have been properly elucidated. Large channels, running along the a direction, contain water molecules and 1,3-diammoniopropane cations that are strongly hydrogen bonded to the anionic framework through N+ÐH O and OÐH O interactions. One vanadyl (V O) bond and the central ±CH2± group of 1,3-diammoniopropane are located on a mirror plane

Efficient tabling of structured data with enhanced hash-consing

Current tabling systems suffer from an increase in space complexity, time complexity or both when dealing with sequences due to the use of data structures for tabled subgoals and answers and the need to copy terms into and from the table area. This symptom can be seen in not only B-Prolog, which uses hash tables, but also systems that use tries such as XSB and YAP. In this paper, we apply hash-consing to tabling structured data in B-Prolog. While hash-consing can reduce the space consumption when sharing is effective, it does not change the time complexity. We enhance hash-consing with two techniques, called input sharing and hash code memoization, for reducing the time complexity by avoiding computing hash codes for certain terms. The improved system is able to eliminate the extra linear factor in the old system for processing sequences, thus significantly enhancing the scalability of applications such as language parsing and bio-sequence analysis applications. We confirm this improvement with experimental results.Comment: 16 pages; TPLP, 201

Heterodimetallic germanium(IV) complex structures with transition metals

The hydrothermal synthesis and structural characterization of a number of complex compounds containing the divalent tris(oxalato-O,O¢)germanate anion, [Ge(C2O4)3]2-, or the neutral bis(oxalate-O,O¢)germanium fragment, [Ge(C2O4)2], with transition-metal (M) cationic complexes of 1,10¢-phenanthroline (phen) is reported: [M(phen)3]- [Ge(C2O4)3]âxH2O [where M2+ ) Cu2+ (1a and 1b), Fe2+ (2a and 2b), Ni2+ (3), Co2+ (4); x ) 0.2 for 2b], [MGe- (phen)2(í2-OH)2(C2O4)2] [where M2+ ) Cd2+ (5) and Cu2+ (6)]. The isolation of two polymorphs with Cu2+ (1a and 1b) and other pseudo-polymorphs for Fe2+ (2a and 2b) was rationalized based on slightly different molar ratios for the starting materials. All compounds have been characterized using EDS, SEM, vibrational spectroscopy (FT-IR and FT-Raman), thermogravimetry, and CHN elemental composition and their structure determined on the basis of single-crystal X-ray diffraction studies. The crystal packing of the different chemical moieties for each series of compounds was discussed on the basis of the various intermolecular interactions present (strong C-Hâââð and weak C-HâââO hydrogen-bonding interactions, C-Hâââð and ð-ð contacts).FCT - SFRH/BPD/9309/2002FCT - SFRH/BPD/14410/2003FEDERPOCI - 201

Decaaqua­dioxidobis[μ3-N-(phospho­n­atometh­yl)imino­diacetato]­dizinc(II)­divanadium(IV) dihydrate

The title compound, [Zn2V2(C5H6NO7P)2O2(H2O)10]·2H2O, contains a [V2O2(pmida)2]4− dimeric anionic unit [where H4pmida is N-(phosphono­meth­yl)imino­diacetic acid] lying on a centre of symmetry which is exo-coordinated via the two deprotonated phospho­nate groups to two Zn2+ cations, with the coordination environment of Zn completed by five water mol­ecules. The crystal packing is mediated by an extensive network of strong and highly directional O—H⋯O hydrogen bonds involving the water mol­ecules (coordinated and uncoordinated) and the functional groups of pmida4−, leading to a three-dimensional supra­molecular network

Crystal structure, topology, tiling and photoluminescence properties of 4d-4f hetero-metal organic frameworks based on 3,5-pyrazoledicaboxylate

Reaction of lanthanide oxides, cadmium acetate and 3,5-pyrazoledicarboxylic acid under hydrothermal conditions afforded five new isostructural 4d-4f hetero-metal organic frameworks, [Cd(3)Ln(pdc)(3)(H2O)] {H(3)pdc = 3,5-pyrazoledicarboxylic acid, Ln = La (1), Pr (2), Nd (3), Sm (4) and Eu (5)}. All compounds were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The compounds feature a very interesting 3D structure built up from a secondary building unit, [Cd(12)Ln(8)(pdc)(6)], and possess a new topology type and complicated unique tiling. The solid state photoluminescence properties of compounds 3-5 were investigated at room temperature

Cytogenetic characterization of two species of Frieseomelitta Ihering, 1912 (Hymenoptera, Apidae, Meliponini)

The cytogenetic analysis of Frieseomelitta dispar and F. francoi revealed the chromosome numbers 2n = 30 and n = 15 and a karyotypic formula 2K = 4M+2Mt+4A+20AM. The number of chromosomes observed was consistent with those reported for other Frieseomelitta species. The occurrence of the Mt chromosome and other features of the karyotype formulae suggest a close relationship between F. dispar, F. francoi and F. varia. Nevertheless, it was possible to differentiate the karyotypes of the species by DAPI/CMA3 staining, which revealed GC-rich regions on two chromosome pairs of F. dispar: one acrocentric and one pseudoacrocentric. In F. francoi, the same kinds of regions were observed on a pair of metacentrics and on a pair of acrocentrics. Our analysis also confirmed the chromosome number conservation in Frieseomelitta and suggests that infrequent pericentric inversion could constitute a synapomorphy for the group including F. dispar, F. francoi, and F. varia

Involving local communities for effective citizen science: determining game species' reproductive status to assess hunting effects in tropical forests

Involving communities in sustainable wildlife management in tropical forests can ensure food security and livelihoods of millions of forest dwellers that depend on wild meat, and also safeguard hunted species. Mathematical models have been developed to assess hunting sustainability; but these require empirical information on reproductive parameters of the prey species, often challenging to obtain. Here, we suggest that if local people can accurately identify the reproductive status of hunted animals in the field, these data could fill the existing knowledge gap regarding species' life-history traits and enable better assessments of hunting impacts. We first tested whether local people in 15 rural communities in three Amazonian sites could accurately diagnose, before and after training, the pregnancy status of hunted pacas Cuniculus paca, which we use as our model. We then applied the results from these tests to correct reproductive status data of hunted specimens, voluntarily collected over 17 years (2002–2018) as part of a citizen-science project in one of our study sites. We ran generalized additive models to contrast these corrected reproductive rates with those obtained from the direct analysis of genitalia by researchers, and with indices describing game extraction levels (catch-per-unit-effort, CPUE, and age structure of hunted individuals). Before training, interviewees correctly diagnosed pregnancy in 72.5% of tests, but after training, interviewees accurately diagnosed pregnancy in 88.2% of tests, with high improvements especially for earlier pregnancy stages. Monthly pregnancy rates determined by hunters and by researchers were similar. Reported annual pregnancy rates were negatively correlated with CPUE, and positively correlated with the percentage of immatures in the hunted population, in accordance with an expected density-dependent response to variations in hunting levels. Synthesis and applications. We show that the voluntary diagnosis of game species' reproductive status by local people is a feasible method to obtain accurate life-history parameters for hunted tropical species, and to assess hunting effects on game populations. Given that almost half of the protected areas in the world are co-managed by local people, our results confirm the potential of integrating local communities in citizen-science initiatives to ensure faster, low-cost and more accurate data collection for wildlife management