Effects of age and sex ratios on offspring recruitment rates in translocated black rhinoceros

Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short‐term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer‐term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations. We used the offspring recruitment rate (ORR) of translocated females—a metric integrating survival, fecundity, and offspring recruitment at sexual maturity—to detect determinants of success. Our unambiguously best model (AICω = 0.986) predicted that ORR increases with female age at release as a function of lower postrelease adult rhinoceros sex ratio (males:females). Delay of first postrelease reproduction and failure of some females to recruit any calves to sexual maturity most influenced the pattern of ORRs, and the leading causes of recruitment failure were postrelease female death (23% of all females) and failure to calve (24% of surviving females). We recommend translocating older females (≥6 years old) because they do not exhibit the reproductive delay and low ORRs of juveniles (<4 years old) or the higher rates of recruitment failure of juveniles and young adults (4–5.9 years old). Where translocation of juveniles is necessary, they should be released into female‐biased populations, where they have higher ORRs. Our study offers the unique advantage of a long‐term analysis across a large number of replicate populations—a science‐by‐management experiment as a proxy for a manipulative experiment, and a rare opportunity, particularly for a large, critically endangered taxon such as the black rhinoceros. Our findings differ from previous recommendations, reinforce the importance of long‐term data sets and comprehensive metrics of translocation success, and suggest attention be shifted from ecological to social constraints on population growth and species recovery, particularly when translocating species with polygynous breeding systems.     

Biodegradability and compostability of polymers—test methods and criteria for evaluation

The treatment of solid waste in controlled composting facilities is an important possibility for reducing garbage. Natural and synthetic polymeric materials can be used for many purposes, for example, as packaging materials, where compostability is required. A prerequisite for official regulations and the decision as to which materials may be composted is investigations on their biodegradability and the quality of the compost produced. Several standardization groups at the ISO, CEN, and DIN are developing definitions, test methods, and classification systems for differentiating compostable from noncompostable materials. The concept which will be standardized and used in Germany is described in detail. It includes characterization of the test material, determination of the biodegradability using laboratory tests such as simple aquatic batch tests and a controlled aerobic composting test, investigation of the disintegration of the test material in industrial or bench-scale composting facilities, and finally, chemical and ecotoxicological analysis of the compost produced.     

Chemical behavior of organic compounds in the interface of water/dual-cation organobentonite

The sorption behavior of polar of ionizable organic compounds,such as p-nitrophenol,phenol and aniline,in the water/organobentonite systems is investigated.Both adsorption and partition occur to the sorption of organic compounds to dual-cation organobentonites.The separate contributions of adsorption and partition to the total sorption of organic compounds to dual-cation organobentonites are analyzed mathematically in the first time.The factors to the contributions are also discussed.The results indicated that the contribution of adsorption and partition is related to the composition and ratio of dual-cation surfactants exchanging onto the bentonite.The sorption of organic compounds to dual-cation organobentonite is dominated by adsorption at low concentrations and by partition at high concentrations,making the organobentonites powerful sorbents for organic contaminants over wide range of concentrations.     

Prenatal diagnosis of trisomy 9 mosaicism: Two new cases

We present two prenatal cases of trisomy 9 mosaicism, both of which presented intrauterine growth retardation (IUGR) and other abnormal ultrasound findings. In case A, mosaicism was found in amniotic fluid cell cultures, of which 65 per cent were trisomic cells, on average. In case B, trisomic cells were present in amniotic fluid cell cultures (12 per cent) but none were found in fetal cord blood. After autopsy, cytogenetic findings were confirmed in different tissue cultures. It is concluded that echographic indicators are a very useful tool for a correct prenatal diagnostic interpretation of trisomy 9. Suspected trisomy 9 mosaicism always requires further investigation and fetal cord blood cytogenetic analysis may not be considered as providing an accurate diagnosis of fetal trisomy 9.     

Mosaicism of isochromosome 18p.

The first case of isochromosome 18p as a mosaic in a male fetus diagnosed by amniocentesis is reported. After termination of the pregnancy at 21 weeks gestation biopsies from different fetal organs as well as from the placenta were taken and set up for long term cell cultures. The distribution of the normal and abnormal cell-line in fetal organs was unequal. Unexpectedly the metaphases in the placenta and the lymphocyte culture all showed a normal karyotype. The tetrasomy 18p is associated with a uniform phenotype, even in fetal life, characterized by a small head with protuberant occiput, low-set ears with posterior rotation, epicanthic fold, sharp pinched nose, convex and poorly formed philtrum, high-arched palate, retrognathia, flexion contractures of fingers, short and broad hallux, hypoplastic penis, angulation of clavicles and mild scoliosis. The propositus showed no growth retardation.     

Prenatal diagnosis of trisomy 9 mosaicism possibly limited to fetal membranes

In repeat amniotic fluid cultures mosaicism due to trisomy 9 was noted. Autopsy of the aborted female fetus showed a sinus urogenitalis and gonadal dysgenesis with absence of germ cells only. Fetal lymphocytes and skin fibroblasts had a normal karyotype but trisomy 9 was found in cells grown from placenta. It is likely that trisomic cells were limited to fetal membranes.     

对硝基苯酚在沉积物上的吸附特征---吸附等温线和吸附热力学

研究了对硝基苯酚在不同沉积物上的吸附等温线,比较分析了Linear方程、Freundlich方程和Langmuir方程描述吸附等温线的准确性和稳定性结果表明,Iinear方程更适合描述沉积物吸附对硝基苯酚的等温线对硝基苯酚在沉积物上的吸附主要是溶质在沉积物有机质中的分配,其吸附热为-7 8 kJ@mol-1,主要的吸附作用力为疏水键力.对硝基苯酚在18个沉积物有机质上吸附自由能改变量为-5 4--7.2kJ@mol-1.标准自由能的变小是对硝基苯酚在沉积物有机质上吸附的推动力.     

Prenatal diagnosis of Pallister–Killian syndrome: Resolution of cytogenetic ambiguity by use of fluorescent in situ hybridization

We report a case of Pallister-Killian syndrome initially diagnosed prenatally as tetrasomy 21. A 33-year-old primiparous woman was noted at 24 weeks' gestation to have moderate polyhydramnios. Ultrasonography showed diminished fetal stomach filling, hydronephrosis, and prominence of the cisterna magna. Cytogenetic analysis of cultured amniocytes was initially interpreted as mosaic tetrasomy 21: 46,XX/47,XX,+i(21q). The patient was then referred to our centre for genetic counselling. At 34 weeks' gestation, a dysmorphic infant was delivered and died within 30 min. Physical features were consistent with the Pallister-Killian syndrome. Renal, gastrointestinal, and central nervous system anomalies were found at post-mortem examination. Analysis of peripheral lymphocytes revealed 5 per cent of cells with a marker chromosome, while 92 per cent of cultured fibroblasts had this same marker. Fluorescent in situ hybridization (FISH) using an alpha-satellite probe for chromosomes 13 and 21 failed to hybridize to the marker, while a chromosome 12 centromeric probe unequivocally identified it as an i(12p). Use of FISH can provide rapid, specific prenatal diagnosis of ambiguous marker chromosomes and improve prenatal counselling.     

灌溉污水中苯并(a)芘最高容许浓度的探讨

苯并(a)芘是一种强致癌物,在环境和食品中普遍存在,并能在土壤和生物体内蓄积,最高容许浓度的确定应考虑到环境中的“本底”水平和灌溉水中的实际含量以及对机体的毒理危害程度,建议灌溉污水中苯并(a)芘的最高容许浓度为0.05μg/L.     

纳米Fe3O4的制备及其对对硝基甲苯的催化降解

采用共沉淀法制备了纳米四氧化三铁（Fe3O4），并进行必要表征，制备所得的Fe3O4粒径与商品Fe3O4相当，均为15～20nm。在中性、碱性条件下，制备的材料表面带负电，而在弱酸性条件下，则带正电。制备出的Fe3O4与商品的Fe3O4一样，对对硝基甲苯具有相同的机械催化降解效率，均符合准一级反应动力学。