Assessing Metal Exposure and Leaching from Discarded Cigarette Butts: Environmental Analysis and Integrated Waste Management Approaches.

Cigarette butts, often discarded as litter, are considered a common form of waste, containing a variety of pollutants within this hazardous residue. This study, which was designed to assess the environmental release of certain metals from cigarette butts, investigates a variety of scenarios under varying climatic conditions. Thus, in order to assess the level of metal contamination, samples of cigarette butts were collected in urban areas from seven popular brands in China, smoked artificially, and examined through graphite furnace atomic absorption (GF-AAS). The findings indicated mean concentrations of 1.77 for Cr, 2.88 for Ni, 12.93 for Cu, 24.25 for Zn, and 1.77 µg/g for Pb in the case of newly smoked butts. The emission of each of the metals increases to 8-10% when cigarette butts remain in the environment for an extended period of time. Furthermore, rainfall can accelerate metal leaching, reaching values of 18-20% compared to the controlled scenario. The worst-case scenario releases 2129.31 kg/year of metals into the environment, while the best-case scenario sees a lower release of 844.97 kg/year. The data reflect variations in metal emissions across different scenarios. There was also a strong correlation between cigarette butts in public spaces and cities. This research highlights the need to educate smokers and increase urban maintenance efficiency to reduce this litter and the metals it leaches into the environment.

Evolution of Endogenous Retroviruses in the Subfamily of Caprinae.

The interest in endogenous retroviruses (ERVs) has been fueled by their impact on the evolution of the host genome. In this study, we used multiple pipelines to conduct a de novo exploration and annotation of ERVs in 13 species of the Caprinae subfamily. Through analyses of sequence identity, structural organization, and phylogeny, we defined 28 ERV groups within Caprinae, including 19 gamma retrovirus groups and 9 beta retrovirus groups. Notably, we identified four recent and potentially active groups prevalent in the Caprinae genomes. Additionally, our investigation revealed that most long noncoding genes (lncRNA) and protein-coding genes (PC) contain ERV-derived sequences. Specifically, we observed that ERV-derived sequences were present in approximately 75% of protein-coding genes and 81% of lncRNA genes in sheep. Similarly, in goats, ERV-derived sequences were found in approximately 74% of protein-coding genes and 75% of lncRNA genes. Our findings lead to the conclusion that the majority of ERVs in the Caprinae genomes can be categorized as fossils, representing remnants of past retroviral infections that have become permanently integrated into the genomes. Nevertheless, the identification of the Cap_ERV_20, Cap_ERV_21, Cap_ERV_24, and Cap_ERV_25 groups indicates the presence of relatively recent and potentially active ERVs in these genomes. These particular groups may contribute to the ongoing evolution of the Caprinae genome. The identification of putatively active ERVs in the Caprinae genomes raises the possibility of harnessing them for future genetic marker development.

Quantifying the influence of urban road surface roughness on heavy metals pollution in road-deposited sediment's accumulation and wash-off.

Surface roughness is an important factor to consider when evaluating the loads of surface runoff caused by road-deposited sediment (RDS) wash-off and creating management solutions for this occurrence in metropolitan areas. Nevertheless, the implications of surface roughness on RDS development and escape remain unclear due to a paucity of experimental evidence distinguishing the significance of surface roughness. This research aimed to differentiate the impact of surface roughness on RDS accumulation and wash-off by employing paired asphalt, rainfall simulation designs, and concrete road surfaces. Our findings indicated that normal asphalt surfaces are typically rougher than typical concrete surfaces because they frequently contain deeper depressions. Compared to concrete surfaces, asphalt surfaces typically retain more RDS, a higher proportion of coarse aggregates, more RDS wash-off loads, and a lower proportion of wash-off. Surface roughness has varying impacts on the RDS motilities of particulates of varying sizes during rainy runoff; nevertheless, the settleable particles (40-150 µm) were more noticeably impacted by it. The first flush effect also seemed to be more pronounced on surfaces with lower roughness. Hence, surface roughness has a significant impact on how RDS builds on and is washed off of various road aspects.

Insertion of 643bp Retrotransposon Upstream of PPARγ CDS Is Associated with Backfat of Large White Pigs.

PPARs are essential regulators of mammalian fatty acid and lipid metabolism. Although the effects of genetic variations, including single nucleotide polymorphisms (SNPs) in PPARs genes on the phenotype of domestic animals have been investigated, there is limited information on the impact of retrotransposon insertion polymorphisms (RIPs). In this study, a combined comparative genome and polymerase chain reaction (PCR) was used to excavate the RIPs in porcine PPARs. We also investigated the potential effects of retrotransposon insertion on phenotype and expression patterns. This study identified the two RIPs in PPARs genes, namely an ERV in intron 1 of PPARα and a combined retrotransposon in intron 2 of PPARγ, designated as PPARα-ERV-RIP and PPARγ-COM-RIP, respectively. These RIPs exhibited different distribution patterns among Chinese indigenous breeds and Western commercial breeds. Individuals with the PPARα-ERV-RIP+/+ genotype (+/+ indicated homozygous with insertion) among Large White pigs had significantly higher (p < 0.05) corrected backfat thickness compared to those with the other two genotypes. Similarly, those with the PPARγ-COM-RIP-/- genotype had significantly higher (p < 0.05) corrected backfat thickness than those with the other two genotypes in Large White pigs. Moreover, in 30-day-old Sujiang piglets, the PPARγ gene expression in the backfat of those with the PPARγ-COM-RIP-/- genotype (-/- indicated homozygous without insertion) was significantly greater (p < 0.01) than those with other genotypes. The dual luciferase reporter gene assay demonstrated that the combined retrotransposon insertion significantly reduced the activity of the MYC promoter in both C2C12 and 3T3-L1 cells (p < 0.01). Therefore, the combined retrotransposon insertion could function as a repressor to decrease the expression of PPARγ, making PPARγ-COM-RIP a valuable molecular marker for assisted selection of backfat thickness in pig breeding.

SINE Insertion in the Pig Carbonic Anhydrase 5B (CA5B) Gene Is Associated with Changes in Gene Expression and Phenotypic Variation.

Transposons are genetic elements that are present in mammalian genomes and occupy a large proportion of the pig genome, with retrotransposons being the most abundant. In a previous study, it was found that a SINE retrotransposon was inserted in the 1st intron of the CA5B gene in pigs, and the present study aimed to investigate the SINE insertion polymorphism in this gene in different pig breeds. Polymerase chain reaction (PCR) was used to confirm the polymorphism in 11 pig breeds and wild boars), and it was found that there was moderate polymorphism information content in 9 of the breeds. Further investigation in cell experiments revealed that the 330 bp SINE insertion in the RIP-CA5B site promoted expression activity in the weak promoter region of this site. Additionally, an enhancer verification vector experiment showed that the 330 bp SINE sequence acted as an enhancer on the core promoter region upstream of the CA5B gene region. The expression of CA5B in adipose tissue (back fat and leaf fat) in individuals with the (SINE+/+) genotype was significantly higher than those with (SINE+/-) and (SINE-/-) genotypes. The association analysis revealed that the (SINE+/+) genotype was significantly associated with a higher back fat thickness than the (SINE-/-) genotype. Moreover, it was observed that the insertion of SINE at the RIP-CA5B site carried ATTT repeats, and three types of (ATTT) repeats were identified among different individuals/breeds (i.e., (ATTT)4, (ATTT)6 and (ATTT)9). Overall, the study provides insights into the genetic basis of adipose tissue development in pigs and highlights the role of a SINE insertion in the CA5B gene in this process.

Artificial neural network (ANN)-based estimation of the influence of COVID-19 pandemic on dynamic and emerging financial markets.

The COVID-19 pandemic is a serious global issue destroying financial markets awfully. The proper estimation effect of COVID-19 pandemic on dynamic emerging financial markets is a big challenge due to a complex multidimensional data. However, the present study proposes a Deep Neural Network (DNN)-based multivariate regression approach with backpropagation algorithm and structural learning-based Bayesian network with constraint-based algorithm to investigate the influence of COVID-19 pandemic on the currency and derivatives markets of an emerging economy. The output shows that the COVID-19 pandemic has negatively influenced the financial markets as indicated by sharply depreciating currency value around 10 % to 12 % and reducing short-position of futures derivatives around 3 % to 5 % for currency risk hedging. The robustness estimation shows that there have probabilistic distributed between Traded Futures Derivatives Contracts (TFDC), Currency Exchange Rate (CER), and Daily Covid Cases (DCC) and Daily Covid Deaths (DCD). Moreover, the output represents that the futures derivatives market conditionally depends on the currency market volatility given percentage of COVID-19 pandemic. This study may help to policymakers of financial markets in decision-making to control CER volatility that may promote currency market stability to enhance currency market activities and boost confidence of foreign investors in extreme financial crisis circumstances.

Two Retrotransposon Elements in Intron of Porcine BMPR1B Is Associated with Phenotypic Variation.

It has been established that through binding to bone morphogenetic proteins (BMPs), bone morphogenetic protein receptor I B (BMPR1B) can mediate transforming growth factor ß (TGF-ß) signal transduction, and is involved in the regulation of several biological processes, such as bone and muscle formation and homeostasis, as well as folliculogenesis. Also known as FecB, BMPR1B has been reported as the major gene for sheep prolificacy. A number of previous studies have analyzed the relationship between single nucleotide polymorphisms (SNPs) in this gene and its related performance. In recent years, with the illustration of the effect of retrotransposon insertion on the expression of the proximal genes or phenotypic variation, retrotransposon insertion polymorphisms (RIPs) have been used as a novel type of molecular marker in the evaluation of evolution, population structure and breeding of plant and domestic animals. In this study, the RIPs in porcine BMPR1B gene were excavated, and thereafter verified using a comparative genome and polymerase chain reaction (PCR). The potential effects of phenotype, gene expression and functions related to RIPs were also explored. The results showed that 13 distinct RIPs were identified in introns of porcine BMPR1B. Among these, only BMPR1B-SINE-RIP9 and BMPR1B-LINE-RIP13 displayed a close relationship with the growth traits of Large White pigs. Moreover, the total number of BMPR1B-SINE+/+-RIP9 individuals born was found to be significantly higher than that of SINE−/− (p < 0.05). These two RIPs showed an obvious distribution pattern among Chinese indigenous breeds and Western commercial breeds. The expression of BMPR1B in ovaries of adult BMPR1B-SINE+/+-RIP9 Sushan pigs was found to be significantly higher in comparison to those of BMPR1B-SINE−/−-RIP9 (p < 0.05). SINE insertion of BMPR1B-SINE-RIP9 and LINE insertion of BMPR1B-LINE-RIP13 were observed to significantly increase the activity of Octamer binding transcription factor 4 (OCT4) minipromoter in CHO and C2C12 cells (p < 0.01). Therefore, these two RIPs could serve as useful molecular markers for modulating the growth or reproductive traits in assisted selection of pig breeding, while the mechanisms of the insertion function should be studied further.

SINE Insertion May Act as a Repressor to Affect the Expression of Pig LEPROT and Growth Traits.

Retrotransposon is an important component of the mammalian genome. Previous studies have shown that the expression of protein-coding genes was affected by the insertion of retrotransposon into the proximal genes, and the phenotype variations would be related to the retrotransposon insertion polymorphisms (RIPs). In this study, leptin (LEP), leptin receptor (LEPR), and leptin receptor overlapping transcript (LEPROT), which play important roles in the regulation of fat synthesis and body weight, were screened to search for the RIPs and their effect on phenotype and gene expression, as well as to further study the function of the insertion. The results showed that three RIPs located in intron 1 of LEPROT and intron 2 and 21 of LEPR were identified, and they were all SINEA1, which was one type of retrotransposon. The SINE insertion at the LEPROT was the dominant allele in native pig breeds. The age of 100 kg body weight of SINE+/+ Large White individuals was significantly higher than those of SINE+/− and SINE−/− individuals (p < 0.05). The LEPROT gene expression in the liver and suet of 30-day-old SINE−/− Sujiang piglets were significantly higher than those of SINE+/+ and SINE+/− piglets (p < 0.01). The dual-luciferase reporter gene assay showed that SINE insertion in PK15 and 3T3-L1 cells significantly reduced the promoter activity of the LEPROT gene (p < 0.01). Therefore, SINE insertion can be a repressor to reduce the expression of LEPROT and could be a useful molecular marker for assisted selection of growth traits in pig breeding.

Measurement and analysis of the resilience characteristics for a regional agricultural soil-water resource composite system.

Resilience is a significant attribute used to measure the sustainable development of the environment, and research on optimal measurement models is very important. This study took 15 farms in the Jiansanjiang Administration of Heilongjiang Province in China as the research object and constructed a resilience evaluation indicator system containing 31 indicators for the regional agricultural soil-water resource composite system (ASWRS). The combined weight (BFCM-CRITIC) and entropy weight (EW) combined with the variable fuzzy assessment (VFA) model and the improved technique for order preference by similarity to an ideal solution (TOPSIS) model were used to calculate the resilience exponent and to analyse the characteristics of space-time variation. The stability and reliability of the two models under different weights were verified by the Spearman correlation coefficient and discrimination theory to determine the optimal resilience exponent diagnosis method. The results show that according to the BFCM-CRITIC-VFA model, the levels of resilience were the highest at the Nongjiang, Hongwei and Erdaohe farms, and the resilience levels were strong and scattered. The resilience of the Jiansanjiang Administration has been increasing over time, and the spatial distribution has generally decreased from north to south and from the Heilong River and Wusuli River basins inland. A comparison of the reliability and stability of the two models for different weights indicates that the VFA model optimized based on combined weights was superior to the other methods in terms of stability and reliability, which verifies that the BFCM-CRITIC-VFA model is the most suitable for measuring the resilience exponent.

Genetic Evaluation and Population Structure of Jiangsu Native Pigs in China Revealed by SINE Insertion Polymorphisms.

Short interspersed nuclear elements (SINEs), one type of retrotransposon, are considered to be ideal molecular markers due to their wide distribution in the genome, high copy number, and high polymorphism. Preliminary studies have identified more than 35,000 SINE-retrotransposon insertion polymorphisms (RIPs) in the pig genome. In this study, 18 SINE-RIPs were used to evaluate the genetic variation and population structure of seven native pig populations and two crossbreeds in the Jiangsu Province of China. Two commercial pig breeds (Duroc and Large White) and one Italian native breed (Sicilian Black pig) were selected as the control. The results showed that all 18 SINE-RIPs were polymorphic among these pigs. The Jiangsu native pig populations (Erhualian, Fengjing, Middle Meishan, Mi, Shawutou, Small Meishan, and Huai) were shown to be more polymorphic than the crossbreeds (Sushan and Sujiang) and external breeds (Sicilian Black pig, Large White, and Duroc) based on the expected heterozygosity and polymorphic information content values. Some native pigs, including Small Meishan, Mi, Middle Meishan, and Erhualian, had a higher degree of inbreeding according to the FIS values. Based on the neighbor-joining tree, all of the Jiangsu native pig populations formed one branch, while the three external pig breeds formed the other branches, with the two crossbreeds containing more than 50% external pig ancestry. The Huai pigs were independent of the other Jiangsu native pigs but shared a common ancestor with Sujiang and Mi. The results provide a new perspective on the population structure of these native pig breeds and will assist with the conservation and utilization of Chinese native pigs.

Measurement and analysis of regional flood disaster resilience based on a support vector regression model refined by the selfish herd optimizer with elite opposition-based learning.

Flood disasters are sudden, frequent, uncertain and highly hazardous natural disasters. The precise identification of the spatiotemporal evolution characteristics, key driving factors and influencing mechanisms of resilience has become a hot spot in disaster risk reduction research. Therefore, the cumulative information contribution rate-Pearson correlation coefficient (CICR- PCC) model is used in this paper to construct a flood disaster resilience index system by quantitative methods, and a support vector regression model refined by the selfish herd optimizer with elite opposition-based learning (EO-SHO-SVR) is built to improve the accuracy of flood disaster resilience evaluation. On this basis, the EO-SHO-SVR model is used to analyze the spatiotemporal evolution of flood disaster resilience in the Jiansanjiang branch of China Beidahuang Agricultural Reclamation Group Co., Ltd. over the past 22 years. In addition, to verify the comprehensive performance of the EO-SHO-SVR model, support vector regression (SVR), imperial competition algorithm-improved support vector regression (ICA-SVR), and unimproved selfish herd optimizer support vector regression (SHO-SVR) models were selected for comparative analysis. The results show that during the study period, the resilience levels reached a plateau of high levels from 1997 to 2018 after experiencing a state of steady low levels followed by increased volatility. Among the investigated factors, land-average flood prevention investment, GDP per capita, agricultural machinery power per unit of arable land, water conservancy project investment as a percentage of GDP, and rainfall are the main driving factors that cause spatiotemporal differences in flood disaster resilience in the study area. Spatially, the resilience levels in the Jiansanjiang branch are ordered as northern farms > southern farms > central farms, and the comprehensive index of resilience shows an increasing trend from west to east. In the model comparison, the EO-SHO-SVR model has outstanding advantages in fitting performance, reliability, rationality and stability, which fully demonstrates that the EO-SHO-SVR model is highly advanced and practical in the measurement of flood disaster resilience. These research results can provide a more accurate evaluation model of regional flood disaster resilience. In addition, they can also provide valuable information for regional flood resilience improvement and flood risk avoidance.

SINE Insertion in the Intron of Pig GHR May Decrease Its Expression by Acting as a Repressor.

The genetic diversity of the GH/IGF axis genes and their association with the variation of gene expression and phenotypic traits, principally represented by SNPs, have been extensively reported. Nevertheless, the impact of retrotransposon insertion polymorphisms (RIPs) on the GH/IGF axis gene activity has not been reported. In the present study, bioinformatic prediction and PCR verification were performed to screen RIPs in four GH/IGF axis genes (GH, GHR, IGF1 and IGF1R). In total, five RIPs, including one SINE RIP in intron 3 of IGF1, one L1 RIP in intron 7 of GHR, and three SINE RIPs in intron 1, intron 5 and intron 9 of GHR, were confirmed by PCR, displaying polymorphisms in diverse breeds. Dual luciferase reporter assay revealed that the SINE insertion in intron 1 of GHR significantly repressed the GHR promoter activity in PK15, Hela, C2C12 and 3T3-L1 cells. Furthermore, qPCR results confirmed that this SINE insertion was associated with a decreased expression of GHR in the leg muscle and longissimus dorsi, indicating that it may act as a repressor involved in the regulation of GHR expression. In summary, our data revealed that RIPs contribute to the genetic variation of GH/IGF axis genes, whereby one SINE RIP in the intron 1 of GHR may decrease the expression of GHR by acting as a repressor.

Magneto-hydro dynamic squeezed flow of Williamson fluid transiting a sensor surface.

The present article reports the combined effects of radiation and heat origination on the electro-kinetically induced hydromagnetic squeezed flow of a pseudoplastic fluid. The fluid is passing over a microcantilever sensor surface positioned in the superficial free stream. Microcantiliver sensor can detect the flow rate and the variance in the temperature of the fluid. The thermal conductivity and fluid viscosity are assumed as a function of temperature. Boundary layer approximations are considered to construct a pseudoplastic fluid flow model. The governing system is then resolved into a non-dimensional form with the assistance of an appropriate set of control parameters. The solution to these non-dimensional equations has calculated with the assistance of familiar numerical techniques i.e. Shooting technique. The results specify that flow of fluid, temperature, and velocity profiles are remarkably influenced by the radiation parameter, fluid parameter, heat generation parameter, thermal relaxation parameter, magnetic parameter, and the squeezing number. A comprehensive graphical and tabular study is constructed to check the convergence of the obtained results. One can detect that the temperature curve is changing slightly for the Christov-Cattaneo heat transfer model as compared to classical Fourier's law of heat transfer. Further, the physical quantities, i.e. free stream velocity, variable viscosity, thermal conductivity, Weissenberg number, and Prandtl number have strong impacts on the boundary layer flow equations. It is perceived that the fluid velocity profile rises for the growing value of the magnetic parameter, but reduces for squashed flow index b. Also, a positive variation is found in the temperature profile for rising values of ß and Q .

Discovering interlinkages between major cryptocurrencies using high-frequency data: new evidence from COVID-19 pandemic.

Through the application of the VAR-AGARCH model to intra-day data for three cryptocurrencies (Bitcoin, Ethereum, and Litecoin), this study examines the return and volatility spillover between these cryptocurrencies during the pre-COVID-19 period and the COVID-19 period. We also estimate the optimal weights, hedge ratios, and hedging effectiveness during both sample periods. We find that the return spillovers vary across the two periods for the Bitcoin-Ethereum, Bitcoin-Litecoin, and Ethereum-Litecoin pairs. However, the volatility transmissions are found to be different during the two sample periods for the Bitcoin-Ethereum and Bitcoin-Litecoin pairs. The constant conditional correlations between all pairs of cryptocurrencies are observed to be higher during the COVID-19 period compared to the pre-COVID-19 period. Based on optimal weights, investors are advised to decrease their investments (a) in Bitcoin for the portfolios of Bitcoin/Ethereum and Bitcoin/Litecoin and (b) in Ethereum for the portfolios of Ethereum/Litecoin during the COVID-19 period. All hedge ratios are found to be higher during the COVID-19 period, implying a higher hedging cost compared to the pre-COVID-19 period. Last, the hedging effectiveness is higher during the COVID-19 period compared to the pre-COVID-19 period. Overall, these findings provide useful information to portfolio managers and policymakers regarding portfolio diversification, hedging, forecasting, and risk management.

Synthesis and structural and magnetic characterisation of cobalt(ii) complexes of mixed phosphonate-antimonate ligands.

The polynucleating oxygen donor ligands, [(SbAr)(4)O(2)(PhPO(3)H)(4)(PhPO(3))(4)] 1 and [(SbAr)(2)O(HO(3)P(t)Bu)(6)] 2, based on condensation of p-chlorophenylstibonic acid (ArSbO(3)H(2)) and phosphonic acids, were used to prepare polymetallic cobalt(ii) complexes. Reaction of 1 with cobalt acetate under solvothermal conditions produces three different types of polymetallic cobalt complexes. With LiOMe/pyridine as base in MeOH a dinuclear cobalt cage, [Co(2)(SbAr)(4)O(4)(O(3)PPh)(4)(OMe)(4)py(2)] 3, is formed, with four Sb(ii) and two Co(ii) centres bridged by µ(3)-oxides and phosphonates. The pyridine in the structure can be replaced by 3-picoline 4, 4-picoline 5, quinoline 6, 1,2-diazole 7, 4-phenylpyridine 8, 4-ethyl pyridine 9 and methanol 10. Using pyrazine (pyz) instead of pyridine under the same conditions a polymer, [Co(2)(SbAr)(4)O(4)(O(3)PPh)(4)(OMe)(4)(C(4)H(4)N(2))](n)11, is formed. A similar 1D-polymer forms with 4,4'-bipyridyl-ethylene 12 in place of pyrazine. With Et(3)N/pyridine as base in MeCN a tetranuclear cobalt cage, [Co(4)(SbAr)(5)O(9)(O(3)PPh)(6)(py)(4)] 13, with five Sb(ii) centres forming a "bowtie" and bridging to four Co(ii) centres by phosphonates and µ(3)-oxides, is formed. The reaction of 2 with cobalt acetate using LiOMe/pyridine as base in methanol, under solvothermal conditions, produces a dinuclear Co(ii) complex, [Co(2)(SbAr)(2)(O(3)P(t)Bu)(3)O(2)(OMe)(2)(py)(2)] 14, with two Co(II) and two Sb centres at the vertices of a distorted tetrahedron. Magnetic measurements on selected number of these cobalt cages are reported.

Synthesis and structural and magnetic characterisation of copper(II) complexes of mixed phosphonate-antimonate ligands.

A polynucleating oxygen donor ligand based on condensation of p-chlorophenylstibonic acid (ArSbO(3)H(2)) and t-butylphosphonic acid is reported. [(SbAr)(2)O(HO(3)P(t)Bu)(6)] contains two antimony centres, bridged by an oxide and two hydrogen phosphonates. Reaction with copper acetate under solvothermal conditions produces four new polymetallic copper complexes. With pyridine used as a base the major product is a tetracopper cage, [Cu(4)O(2)(SbAr)(2)(O(3)P(t)Bu)(2)(O(2)CMe)(2)(OMe)(6)], with the four copper centres arranged in a rhombus; a minor product is a tricopper complex, [Cu(3)O(4)(SbAr)(2)(O(3)P(t)Bu)(4)(py)(3)]. With LiOMe as base the major product is again the tetranuclear cage, but the minor product is a heterometallic cage, [Cu(5)Li(4)O(6)(SbAr)(4)(O(3)P(t)Bu)(6)(O(2)CMe)(2)(OMe)(4) (MeOH)(4)]. With 2,6-lutidine as base an octametallic complex is formed, [Cu(8)O(4)(SbAr)(2)(O(3)P(t)Bu)(6)(O(2)CMe)(4)(lutidine)(2)]. Magnetic studies show both anti-ferromagnetic and weak ferromagnetic exchange between the copper centres in these new complexes.

Mixed antimonate-phosphonate ligands as polydentate bridging oxygen donors.

A new class of oxygen donor ligands is described and preliminary results using these ligands are given which show they can be used to make polymetallic cages.