bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of sediment oxygen demand by direct measurement and by inference from reduced species accumulation
Authors: Gelda RK , Auer MT , Effler SW
Published: November 2018

Rates of sediment oxygen demand (SOD) were determined for hypereutrophic Onondaga Lake, New York (USA), by direct and indirect means. The direct approach, laboratory measurements made on intact sediment cores, yielded an average SOD rate of 1.68�0.56 g O2 m-2 day-1. This was essentially equivalent to that determined indirectly by estimating the sediment flux of reduced chemical species (1 .64�0.14 g O2 m-2 day-1). Sulfide, methane, ammonia, and ferrous iron contributed 50, 42, 7, and <1% of the total sediment flux of reduced species, respectively. The sulfide percentage is unusually high for freshwater systems, reflecting the sulfate-rich nature of the lake. Variability in the sediment flux of reduced species over the 3-year study was modest (12%), and rates were consistent with those measured in other systems of similar trophic state. Rates of SOD closely approximated the areal hypolimnetic oxygen deficit of the lake. More than 70% of the SOD was explained by the oxidation of reduced chemical species. These findings suggest that recovery of the oxygen resources of the lake will be mediated primarily through reductions in the delivery of particulate organic matter to the sediments and the rate at which in-place reserves of particulate organic matter are stabilized. The processes of algal respiration and aerobic mineralization of organic matter in the water column, which exhibit a more rapid response to remediation measures, will play a lesser role.
Time-trend analysis of PAH and PCB sediment fluxes in the northern Baltic proper using different dating methods
Authors: Axelman J , Bandh C , Broman D , Carman R , Jonsson P , Larsson H , Linder H , Naf C , Pettersen H
Published: November 2018

A recent laminated sediment was collected in the northern Baltic Proper with a Kajak-type gravity corer. The sediment core was analysed for content of polycyclic aromatic hydrocarbons, (PAHs) and mono-, di- and non-ortho polychlorinated biphenyls (PCBs). To evaluate different dating methods and to make dating as accurate as possible, four sediment-dating methods were used: activity measurements of the radio nuclides 210Pb, 239/240Pu and 137Cs, and counts of the number of laminae in the core. According to the 210Pb dating there was a peak in the annual flux of PAHs and ortho PCBs around 1950 after which the flux declined, but the peaks occurred during the 1970s according to the laminae counts. For non-ortho PCBs the trend was less clear, but a flux increasing with time was evident. Multivariate analysis showed a significant change in PAH composition over time, whereas the PCB composition was relatively constant.
Non-point-source nutrient losses to the aquatic environment in Denmark: impact of agriculture
Authors: Kronvang B , Grant R , Larsen SE , Svendsen LM , Kristensen P
Published: November 2018

As part of a coordinated programme for nationwide monitoring of the Danish aquatic environment, initiated in 1988, nutrient fluxes are measured in 270 rivers, and nutrient cycling is studied in six agricultural catchments. This enables assessment of the degree of non-point-source nutrient loading of Danish surface water and groundwater as well as of the impact of agriculture practised under different climatic and physiographic conditions and with different farming practices.
Comparison of annual median losses of total nitrogen and total phosphorus in agricultural catchments and undisturbed catchments revealed an average loss ratio of 14:l for total nitrogen (23.4 and 1.7 kg N ha-1, respectively) and 4:1 for total phosphorus (0.29 and 0.070 kg P ha-1, respectively).
Assessment of nitrogen cycling in six small agricultural catchments with either sandy soil or loamy soil revealed marked differences in annual net input to the soil (142 v. 77 kg N ha-1), annual leaching from the root zone (154 v. 78 kg N ha-1), and annual riverine loss of nitrogen (13 v. 25 kg N ha-1). The differences in the rates of leaching and riverine loss in the two soil types reflect the different potential for surface-water and groundwater pollution with nitrogen and also the fact that the denitrification potential is higher in both the soil and the riparian areas of sandy ecosystems.
Modelling of data from 77 small representative river basins revealed significant empirical relationships (P <0.001) between annual loss of both nitrogen and phosphorus and various predictor variables (e.g. runoff, proportion of agricultural land, soil type). Runoff and proportion of agricultural land explained, respectively, 41% and 26% of the variance in the nitrogen-model and 45% and 8%, of the variance in the phosphorus model. Such loading models are valuable tools for systems analysis and management at the catchment level, such as when assessing measures implemented to reduce non-point-source nutrient pollution.
Thorium isotopes as indicators of scavenging rates in the Venice Lagoon
Authors: Cochran JK , Frignani M , Hirschberg DJ , Barnes C
Published: November 2018

The naturally occurring thorium isotopes 228Th and 234Th, produced in sea water from decay of 228Ra and 238U, respectively, were used to estimate the rate of scavenging onto particle surfaces and the rate of removal of particles from the water column of the Venice Lagoon. Large water samples (1000-2000 L) were collected at three sites in the shallow (<1 m) waters of the lagoon. Samples were pumped through two 0.5-μm wound filter cartridges to remove particles and then through two MnO2-impregnated cartridges to extract dissolved Th. Activities of particulate 234Th ranged from 510 to 1335 μBq L-1 and dissolved 234Th was <350 μBq L-1. Relative to calculated 238U activities in the lagoon, the 234Th data yielded mean residence times as short as 2 h for the scavenging of dissolved 234Th onto particles and 12 h for the removal of particulate 234Th. Resuspension rates of 0.6 to 8 mg cm-2 day-1 were estimated from the data on dissolved and particulate 234Th, these values being comparable to those determined by sediment traps (1.8-9.5 mg cm-2 day-1) at the same sites. These results suggest that Th and other similarly reactive trace metals are removed rapidly from the waters of the Venice Lagoon to the sediments.
Desorption during resuspension events: Kinetic v. equilibrium model
Authors: Cheng CY , Atkinson JF , DePinto JV
Published: November 2018

The spills and release of hydrophobic organic chemicals (HOCs) into waterbodies have resulted in the contamination of bottom sediments. When these sediments are resuspended by runoff events or by dredging, particulate-phase contaminants desorb to the water phase. Equilibrium between the particulate phase and the dissolved phase is usually assumed for most modelling applications regardless of time scale.
For well mixed systems in which chemical transport is not limited by mass transfer between the bulk water phase and sediment aggregates, an intraparticle diffusion model can be applied to estimate the time required for various HOCs to reach an equilibrium state between dissolved and particulate-phase concentrations. Calculations from this model show that total equilibrium time scales cover a wide range, from less than a day to a few hundred days.
This study compares predicted suspension times for sediments of various sizes with expected equilibration times for desorption. This comparison indicates that the equilibrium assumption is not valid for a wide range of parameter values typical of natural systems. In particular, compounds with high partition coefficients, greater than about 104 mL g-1, will have minimum equilibration times of at least one to ten days. This is likely to be greater than the expected resuspension time.
Mobilization of PAH from polluted seabed and uptake in the blue mussel (Mytilus edulis L.)
Authors: Naes K , Bakke T , Konieczny R
Published: November 2018

In several Norwegian fjords that have received effluents from smelters, there are significant accumulations of polycyclic aromatic hydrocarbons (PAH) in the sediments; near the outfalls, concentrations may reach several hundred μg total PAH g-1. As the smelters are now implementing measures to clean up and reduce discharges, the accumulations from previous discharges could assume greater relative importance as a potential source. In order to give an assessment of the significance of sedimentary PAH 'hot spots' in Norwegian smelter-affected fjords, an experiment was performed in which seabed sediment sections (0.5 × 0.5 m, 1.3 to 543 μg total PAH g-1) were collected from the Oslo-, Sauda- and Sunndalsfjords and placed in an experimental set-up in which Oslofjord water taken from a depth of 40 m was passed over the sediment surfaces. The mobilization experiments indicated that a natural seabed containing 100 μg PAH g-1, and with a resuspension (due to bioturbation) within an expected natural range, might give an annual contribution to the overlying water of the order of 20 kg PAH km-2. Mussels continuously exposed to the water from the test sediments accumulated PAH in a clear response to concentrations in sediments and water and to the degree of resuspension. PAH from the Saudalsfjord were apparently more bioavailable than those from the Sunndalsfjord, and it is argued that a more rapid accumulation in the former case was stimulated by an elevated organic carbon content in the sediment.
Flocculation of sediment from the Tanshui River estuary
Authors: Tsai CH , Hwang SC
Published: November 2018

Experiments on the flocculation of fine-grained sediments from the Tanshui River estuary, Taiwan, were carried out. The effects of fluid shear, sediment concentration and salinity on floc growth were investigated. The ranges of these parameters were 12.5 to 400 s-1 for the shear, 50 to 600 mg L-1 for the sediments concentration and 0% to 100% sea water for the salinity. The results showed the following. (1) The time required to reach a steady state ranges from 2 to 44 h and median floc sizes range from 100 to 520 μm. (2) The steady-state median floc size decreases with the increase in sediment concentration. (3) The floc size increases as the shear increases. (4) Increasing the proportion of sea water from 0% to 50% decreases the floc size to one-fourth of that of freshwater flocs, and a further increase in salinity does not decrease floc size significantly. (5) The time required to reach a steady state decreases with the decrease in shear, the increase in sediment concentration and the increase in salinity. (6) The larger the steady-state flocs, the longer they take to form. Comparison of these results with those obtained in similar studies of Lake Erie sediments shows that the flocculation properties of Tanshui sediments are substantially different from those of Lake Erie sediments. Tanshui sediments are much more difficult to aggregate, but once flocs are formed they are larger. The reasons why different types of sediment behave differently should be studied further.
Spreading model for a turbidity current with reversing buoyancy from a constant-volume release
Authors: Hurzeler BE , Ivey GN , Imberger J
Published: November 2018

Particle-laden flows with buoyant interstitial fluid from constant-volume releases are often encountered in nature and industry. These currents are driven by the excess density of the suspended particles, and although the bulk suspension is negatively buoyant, the buoyant interstitial fluid of the suspension can be detrained through the top of the current. Detrainment of interstitial fluid at the upper interface of the current and settling of particles through the viscous sublayer at the bottom of the current are shown to reduce the current spreading rate to less than that predicted by an inertia-buoyancy balance. Simple relationships are developed for the spreading of such turbidity currents, and these relationships are tested against published laboratory data. These results are then compared with a two-dimensional numerical simulation of the current using a buoyancy-extended k - ε turbulence closure scheme.
Turbidity, particle fluxes and mineralisation of carbon and nitrogen in a shallow coastal area
Authors: Valeur JR , Jensen A , Pejrup M
Published: November 2018

During a research programme carried out in a shallow coastal area (�rhus Bight, Denmark), short-term and long-term particle dynamics were measured continuously for a year in the water column and in the seabed. The research area is a homogeneous accumulation area for fine-grained sediment, with a water depth of 15 m.
Fluxes in the water column were measured at nine depths with a time resolution of one to two weeks during one year, using duplicate sediment traps with an aspect ratio of 5. Significant correlation between turbidity and vertical particle fluxes was found. Continuous measurements close to the bottom gave an indirect measure of the concentration of suspended particles every 5 min. In this way, it was possible to measure resuspension dynamics with a detailed time resolution.
A new method was developed for the separation of downward fluxes of primary and secondary (resuspended) sediment. The net deposition rate of total particulate matter (TPM) found by this method (DTPM = 1050 g m-2 year-1) is in good agreement with the accumulation rate found by 210Pb core datings (ATPM = 890 g m-2 year-1).
The accumulation rate of particulate organic carbon (POC) and total particulate nitrogen (TPN) beneath the benthic mixing layer was five times smaller than the net deposition rate; this is assumed to be caused by mineralization mainly in the benthic mixing layer. Resuspension events are believed to play a major role in mineralization of organic matter and exchange of nutrients with the water column.
Resuspension rates were 10 to 100 times greater than the net deposition rates in all measuring periods. Supply of new, easily resuspendable sediment during the spring phytoplankton bloom dramatically increased the possibility of resuspension.
108 Single-Cell RNA Sequencing Reveals Blastomere Heterogeneity and Early Lineage Specification Events in Bovine Embryos During Major Embryonic Genome Activation
Authors: Lavagi I. , Krebs S. , Simmet K. , Zakhartchenko V. , Wolf E. , Blum H.
Published: November 2018

During early embryonic stages, gene products generated by the embryo acquire control over embryonic development. At the 8- to 16-cell stage, major embryonic genome activation (EGA) occurs in bovine embryos. Morphological observations, such as size of blastomeres and distribution of microvilli, suggest heterogeneity of individual cells already at this developmental stage. To study this heterogeneity on the transcriptome level, we performed single-cell RNA sequencing (scRNA-seq) of 161 blastomeres from 14 in vitro-produced bovine embryos at Day 2 and Day 3 post-fertilization. After removing the zona pellucida, blastomeres were mechanically separated in Ca2+- and Mg2+-free PBS, individually collected, and lysed. Complementary DNA libraries were prepared by the single cell RNA-barcoding and sequencing (SCRB-Seq) protocol. Exogenous RNA was added for quality control and cell specific barcodes and unique molecular identifiers (UMI) were used to enable pooling of libraries and to exclude PCR duplicates, respectively. After sequencing (Illumina HiSEqn 1500; 50 nt reads; Illumina Inc., San Diego, CA, USA), UMI were counted with the published Drop-seq pipeline (45,000 UMI on average per library) and cells with UMI count <2.000 were removed. Data were normalized based on UMI and non-supervised clustering analyses of single-cell data were performed (SC3 and M3Drop R packages). The transcriptome profiles of all individual cells were assigned to 6 clusters with specific sets of genes. Sorting cells according to their transcriptome profiles by the CellTree R package (Bioconductor; https://bioconductor.org/packages/release/bioc/html/cellTree.html) resulted in a linear pseudo-timeline. Furthermore, this tool identified 6 groups of genes (topics). Each of them showed an over-representation of distinct Gene Ontology (GO) terms; topic 1, “translation” and “cell division”; topic 2, GO terms involved in translation, RNA splicing and cell division; topic 3, “translation”; topic 4, “ATP synthesis coupled proton transport”; topic 5, “mitochondrial translational elongation”; topic 6, “organic hydroxyl compound transport”. Moreover, increased expression of PCDH10 (protocadherin 10) was observed in the biologically pseudo-ordered more advanced blastomeres. This gene is known to be predominantly expressed in the inner cell mass (ICM) at the blastocyst stage, suggesting that these cells might become ICM. In summary, our study reveals developmental heterogeneity and hints to early lineage specification events in bovine embryos at the time of major EGA.
11 Early Induction of Luteolysis in Fixed-Time Artificial Insemination Protocols Increases Fertility in Beef Cows
Authors: Borges J. B. , Machado A. B. , Pradebon E. , Dias M. , Bernardi M. , Wiltbank M.
Published: November 2018

Complete luteolysis is essential for pregnancy success in beef cows submitted to fixed-time AI (FTAI) protocols. The objective of this study was to evaluate the effect of prostaglandin F (PGF) administration on Day 7 compared with Day 8 of an FTAI protocol on serum progesterone (P4) concentration, oestrus behaviour, ovulatory follicle (OF) diameter, and pregnancy per AI (P/AI). A total of 469 nonlactating Angus cows [with corpus luteum (CL), n = 359 or without CL, n = 110], body condition score 2.9 ± 0.2 (1 to 5 scale), maintained on pasture were used. Cows received a 1-g progesterone-releasing intravaginal device (Reproneo; GlobalGen, Jaboticabal, Brazil) and 2 mg of oestradiol benzoate i.m. (Syncrogen; GlobalGen) on Day 0. On Day 7, animals were randomly allocated into 2 groups. Cows were treated with 500 μg of sodium cloprostenol, IM (Inducio; GlobalGen), on Day 7 (PGF7, n = 238) or Day 8 (PGF8, n = 231). Then, P4 devices were removed and 0.5 mg of oestradiol cypionate, IM (Cipion; GlobalGen) was injected in all females on Day 8. The FTAI was performed 48 to 52 h after P4 device removal. Females had sacral region painted with appropriate paint (TELL TAIL, GEA, Hamilton New Zealand) on Day 8 to detect expression of oestrus. Transrectal ultrasonography (7.5-MHz linear transducer, MediSono P3V, Wilmington, DE, USA) was performed on Day 0 to detect presence of CL, on Day 10 to measure OF diameter, and on Day 40 to diagnose pregnancy. Blood samples were collected on Days 8 and 10 to measure P4 serum concentration by radioimmunoassay. Oestrus behaviour and pregnancy rate were analysed as binary outcomes using logistic regression (Proc GLIMMIX, SAS; SAS Institute Inc., Cary, NC, USA). OF diameter and P4 concentration were submitted to analysis of variance (Proc GLIMMIX, SAS). The oestrus manifestation was greater (odds ratio = 2.9; P = 0.0002) in females of PGF7 group (91.6%; 218/238) than PGF8 group (78.8%; 182/231). The P/AI of cows that exhibited oestrus was 60.2% (241/400) v. 39.1% (27/69), resulting in higher chance (odds ratio = 2.4) of pregnancy associated with oestrus behaviour (P = 0.0014). Diameter of the OF did not differ (P = 0.0881) between PGF7 (11.7 mm) and PGF8 (11.3 mm). The P/AI was higher (P = 0.0034) for PGF7 (63.9%, 152/238) v. PGF8 (50.2%, 116/231). In group PGF7, P4 on Day 8 did not differ between pregnant (1.7 ng mL−1) and nonpregnant (1.9 ng mL−1) females. However, group PGF8 pregnant females had lower P4 concentration (2.6 ng mL−1) on Day 8 (P = 0.0005) than nonpregnant (3.4 ng mL−1) females. On Day 10, P4 did not differ between treatments (PGF7 = 0.11 ng mL−1 v. PGF8 = 0.09 ng mL−1) and did not affect fertility (P = 0.2515). According to results, OF diameter and P4 concentration on Day 10 were not influenced by the day of PGF administration; however, earlier PGF injection resulted in higher oestrus behaviour and increased fertility.
112 Identification of Solute Carrier Family 5 Member 9 (SLC5A9) as Biomarker of In Vivo and In Vitro Oocyte Developmental Competence
Authors: Manzoni E. F. M. , Bocchi V. , Galli C. , Strillacci M. G. , Stradaioli G. , Brevini T. A. L. , Gandolfi F.
Published: November 2018

The transcriptome associated with the ability of oocytes to support embryogenesis and development remains unclear. The aim of this study was to compare the mRNA expression pattern between oocytes collected from fertile heifers (H) and repeat breeders (RB) using RNAseq. Oocytes were collected by ovum pick-up from Italian Simmental (IS) and Holstein Friesian (HF) heifers that became pregnant at the following oestrus, and from cows of the same breeds classified as RB after they failed to become pregnant for a minimum of 3 consecutive AI. Oocytes from each animal (5 for HF_RB, 3 each for all other groups) were pooled and sequenced using Illumina HiSEqn 2000 (Illumina Inc., San Diego, CA, USA). Principal component analysis showed that HF oocytes clustered away from those of IS, irrespective of the fertility status. However, within breeds, H and RB always clustered apart from each other. This suggests that differences in the transcriptional blueprint between breeds was more prominent than differences related to fertility. However, these were still strong when considering breeds separately, therefore we treated breeds as independent groups and performed differential expression analysis on H v. RB in IS and HF. DESEqn 2 identified 135 differentially expressed genes when we compared H and RB in IS and 2124 in HF. This difference in number of DE genes between the 2 breeds reflects the fact that the variance between H and RB transcriptional patterns in HF is larger than in IS. We looked for genes that were differentially and consistently expressed between H and RB in both breeds and identified 10 genes: histone H2B, exo/endonuclease G, solute carrier family 5 member 9, BH3 interacting domain death agonist, TBK1 binding protein 1, purine-rich element binding protein A, tRNA-yW synthesising protein 1 homologue, Jun oncogene, FRA10AC1 homologue, and SKI oncogene. To validate their potential use as biomarkers, we performed a preliminary in vitro validation by RT-qPCR. As described in the literature, oocytes collected from ovaries with more than 10 follicles of 2 to 6 mm were classified as high quality, while those collected from ovaries with fewer than 10 follicles were classified as low quality (Gandolfi et al. 1997 Theriogenology 48, 1153-1160). Gene expression analysis confirmed SLC5A9, a membrane-bound protein involved in sodium-dependent transport of glucose, as a potential biomarker to discriminate between a competent and incompetent oocyte. Altogether, our data provide a detailed overview of the mRNA pattern defining the differences between a competent and incompetent oocyte in vivo, and identified a new potential marker able to differentiate fertile and infertile oocyte both in vivo and in vitro.
Study supported by PRIN 08–09, EU-Quantomics no. 222664 and Carraresi Foundation.
142 Isolation of the Quail Spermatogonia
Authors: Mennibaeva E. R. , Volkova N. A. , Tomgorova E. K. , Volkova L. A. , Bagirov V. A. , Zinovieva N. A.
Published: November 2018

Spermatogonia are testicular stem cells, the precursors of male sex cells. They are target cells for introduction of recombinant DNA and suitable for creation of cryobanks to preserve biological materials. The aim of our research was to optimize the individual stages culturing quail spermatogonia. In an initial study, dynamics of change in the composition of spermatogenic cells in the seminiferous tubules were assessed histologically, at weekly intervals from 1 week to 1.5 months of age. Thereafter, spermatogonia were isolated from quail testes. Disaggregation of the testis tissue was carried out by consecutive enzymatic treatment in 0.25% trypsin and 0.1% collagenase solution. Purification of spermatogonia from other types of spermatogenic cells was conducted by separation of the cells by adhesion. The duration and conditions of cultivation of spermatogenic cells were selected experimentally. Cultivation of spermatogonia was performed on feeder layers, including quail primary Sertoli cells, STO cell line, and transplanted porcine Sertoli cells. Growth medium for culturing spermatogonia was DMEM HG medium supplemented with 5% FCS, 2 mM α-glutamine, MEM (10 μL mL−1), antibiotic (100×), insulin-transferrin-selenium (ITS, 10 μL mL−1), 2-mercaptoethanol (5 × 10−5 M), albumin (5 mg mL−1), epidermal growth factor (EGF, 20 ng mL−1), basic fibroblast growth factor (bFGF, 10 ng mL−1), and leukemia inhibitory factor (LIF, 2 ng mL−1). For identification of spermatogonia colonies, SSEA-1 antibodies were used. The maximum number of spermatogonia in seminiferous tubules of quail occurred at 3 weeks of age; there were mainly spermatogonia and Sertoli cells at this time. The percentage of spermatogonia from the total number of spermatogenic cells in the seminiferous tubule reached 76 ± 2%. In view of this, spermatogonia were isolated from the testes of 2-week-old quail. Spermatogenic cells were cultured for 24 h, after which the supernatant with unattached cells, mainly spermatogonia, was transferred to a new dish and cultured. Maximum homogeneity of the cell population was detected by dividing the cells by 3-fold transfer of the cell supernatant at an interval of 24 h; the proportion of spermatogonia in the suspension reached 88%. Quail Sertoli cells were the optimal feeder layer for cultivation of quail spermatogonia. Formation of spermatogonia colonies was observed on Day 5 to 7 of cultures, and their identity confirmed by immunohistochemical staining for SSEA-1.
The study was supported by the Russian Science Foundation within Project no.16-16-04104.
17 Relationship Between Semen Parameters and Morphometric Characteristics of Zulu Rams
Authors: Ngcobo J. N. , Maqhashu A. , Ramukhithi F. V. , Kruger L. P. , Nephawe K. A. , Nedambale T. L.
Published: November 2018

Zulu sheep is an adapted breed of South Africa with desirable traits such as their ability to thrive in a harsh environment and tolerant to various diseases. However, they are endangered, with their population size not exceeding 1000, and hence are associated with high inbreeding rates. Therefore, to limit biodiversity loss, there is a need to characterise and conserve its genetic materials. The aim of the study was to evaluate the relationship between morphometric characteristics and semen parameters of Zulu rams and conserve these genetics. The study was conducted at the Agricultural Research Council. Rams (n = 6, age = 3 years and average weight = 42 kg) were fed a standard diet and water was provided ad libitum. Semen was collected twice a week, using an artificial vagina, over 4 consecutive weeks. Semen volume, spermatozoa concentration, motility parameters, and viability were evaluated immediately after arrival in the laboratory. The experiment was carried out during breeding season (March to May 2017). Body measurements (rump height, body length, scrotum circumference, body weight, scrotal width, and scrotum length) were measured in the morning following the fasting period (night) using flexible measuring tape. Pearson correlation coefficient in Minitab 17 (Minitab Inc., State College, PA, USA) was used to determine the relationship among variables. A moderate significant correlation (P < 0.001) between body weight and %live spermatozoa (r = 0.46) was observed. Of note, a very weak (r = 0.28) significant correlation (P < 0.05) between scrotum circumference and live spermatozoa was observed. A very weak (r = 0.06) nonsignificant correlation (P > 0.05) was found between scrotum circumference and semen volume. These results indicate that body weight and scrotum circumference provide reliable spermatozoa viability estimates. Positive correlation between scrotum circumference and semen volume shows that scrotum circumference can be used to predict semen volume.
22 Comparing Three Extenders: Hashi, Green Buffer and INRA 96, for Chilled Storage of Bactrian Camel Semen
Authors: Panahi F. , Niasari-Naslaji A. , Seyedasgari F. , Ararooti T. , Adel H. , Kalantari A.
Published: November 2018

Semen preservation remains challenging in the camel industry. The objective of the present study was to compare 3 different extenders for chilled storage of Bactrian camel semen. Semen (n = 9 ejaculates) was collected from camel bulls (n = 2) manually using artificial vagina. Good neat semen, as far as mass vibration concerns, was equally distributed into 3 double-wall vessels filled with 35°C water. The 3 extenders used in the present study were Hashi, Green buffer (IMV, L’Aigle, France), and INRA 96 (IMV). The Hashi extender consisted of Tris, 2.6%; citric acid, 1.35%; glucose, 0.9%; fructose, 0.9%; penicillin G sodium, 1000 IU mL−1; streptomycin sulfate, 1000 mg mL−1 supplemented with 20% plasma egg yolk and 20% camel skim milk; osmolality of 330 and pH of 6.9). Green buffer was supplemented with 20% plasma egg yolk (osmolality of 335 and pH of 6.9). The osmolality and pH of INRA 96 were 310 and 7, respectively. Extenders at a ratio of 1:3 were added to semen followed by pipetting 10 times with an automatic pipettor. The water-jacketed extended specimen was covered with foam and transferred to individual vaccine carrier equipped with 4 ice packs. This system of cooling not only allows the specimen to cool down slowly and reach 4°C after 7 h, but also reduces the viscosity of camel semen. The assessment was carried out 7 and 24 h after semen dilution, when the specimen reached 4°C. Semen viability parameters were assessed after short-term semen preservation in different extenders. Total motility and progressive forward motility were examined subjectively by single operator using Sperm Track (ISAS, Proiser, Spain) after diluting the specimen to achieve 25 × 106 sperm mL−1. Live percentage of sperm was estimated using Eosin B Fast Green staining method. Plasma membrane integrity was assessed using the hypo-osmotic swelling (HOS) test. Following arcsin transformation, data were analysed by GLM procedure followed by Tukey test in SAS (SAS Institute Inc., Cary, NC, USA). At 7 and 24 h, there were no differences among the 3 extenders in total motility of sperm (Hashi: 73 and 67.4%; Green buffer: 71.6 and 62.1%; INRA 96: 70 and 66.2%; P > 0.05), live percentage of sperm (Hashi: 76 and 73%; Green buffer: 70.5 and 65.6%; INRA 96: 77.8 and 70.7%; P > 0.05), or HOS test (Hashi: 52.4 and 45.2%; Green buffer: 49.6 and 40.6%; INRA 96: 57.3 and 51.1%; P > 0.05). However, at the same times, progressive forward motility was similar between Hashi (47.7 and 28.6%) and Green buffer (40 and 23.5%; P > 0.05) but was different between Hashi and INRA 96 (23.6 and 16.7%; P < 0.05). In conclusion, Hashi and Green buffer could be considered suitable extenders to preserve Bactrian camel semen under chilled condition. Further studies with a larger number of bulls and ejaculates are warranted.
40 Gene Expression Profiling of In Vitro-Produced Blastocysts Derived from In Vitro-Matured Bovine Oocytes Vitrified/Warmed in Media Supplemented with a Biopolymer Produced by an Antarctic Bacterium
Authors: Arcarons N. , Vendrell M. , Yeste M. , Mercadé M. E. , López-Béjar M. , Mogas T.
Published: November 2018

Previous reports have demonstrated the beneficial effect of antifreeze glycoprotein supplementation during oocyte vitrification on preventing ice crystal formation and thus enhancing developmental competence after vitrification-warming. Pseudomonas sp. ID1, a bacterium isolated from marine sediment from Antarctica, produces an exopolysaccharide, M1 EPS, as a cold adaptation mechanism. Despite numerous studies on structural and morphological damages induced by cryopreservation in oocytes, few studies have focused on the impact of vitrification on the expression pattern of genes during early embryo development. In the present study, the expression patterns of 6 genes (BAX, BCL2-like 1, DNMT3A, UBE2A, SCLC2A3, and HDAC1) were investigated in Day 8 blastocysts resulting from in vitro-matured oocytes vitrified/warmed in media supplemented with various concentrations of M1 EPS. After 21 h of IVM, 1,062 oocytes were vitrified/warmed in media supplemented with 0, 0.001, 0.01, 0.1, and 1 mg mL−1 M1 EPS. At 24 h of IVM, oocytes were in vitro fertilized and in vitro cultured and the resulting blastocysts were harvested at Day 8 for RNA extraction and qPCR analysis. Fresh, non-vitrified oocytes were used as a control. Analysis of gene expression was performed through Kruskall-Wallis test and followed by Mann-Whitney test, and the level of significance was set at P ≤ 0.05. No significant differences were detected in relative mRNA abundance for SLC2A3, UBE2A, or HDAC-1 between blastocysts derived from vitrified oocytes, regardless of M1 EPS treatment. Expression of DNMT3A was significantly higher in embryos obtained from oocytes vitrified and warmed with 0.1 mg mL−1 M1 EPS compared with other treatment groups. However, no differences in DNMT3A expression were observed when the other vitrified groups were compared. The relative abundance of BAX transcript in embryos from oocytes vitrified in media supplemented with 0.1 mg mL−1 M1 EPS was higher than that in 0 or 0.001 mg mL−1 groups. Embryos from 0.01 and 0.1 mg mL−1 groups showed higher BCL2-like 1 mRNA abundance than those from the 0, 0.001, and 1 mg mL−1 groups. Whereas blastocysts from oocytes vitrified with 0.01 mg mL−1 M1 EPS exhibited the lowest BAX:BCL2-like 1 ratio, no significant differences in BAX:BCL2-like 1 ratio were observed between the other treatments. The significantly lower BAX:BCL2 ratio observed in blastocysts obtained from oocytes vitrified with 0.01 mg mL−1 M1 EPS could be indicative for a better embryo quality. Although optimizing the use of M1 EPS may benefit oocyte cryopreservation protocols, further research is required to clarify the exact mechanism through which it exerts its protective role.
This study was supported by the Spanish Ministry of Science and Innovation (Project AGL2016-79802-P and grant CTQ2014-59632-R).
Corrigendum to: Phylogeny, major clades and infrageneric classification of Corymbia (Myrtaceae), based on nuclear ribosomal DNA and morphology
Authors: Parra-O. Carlos , Bayly Michael J. , Drinnan Andrew , Udovicic Frank , Ladiges Pauline
Published: November 2018

Phylogenetic relationships of sections and species within Corymbia (Myrtaceae), the bloodwood eucalypts, were evaluated by using combined analyses of nuclear rDNA (ETS + ITS) and morphological characters. Combining morphological characters with molecular data provided resolution of relationships within Corymbia. The analyses supported the monophyly of the genus and recognition of the following two major clades, treated here as new subgenera: subgenus Corymbia, including informal sections recognised by Hill and Johnson (1995), namely Rufaria (red bloodwoods), Apteria and Fundoria; and subgenus Blakella, including sections Politaria (spotted gums), Cadagaria, Blakearia (paper-fruited bloodwoods or ghost gums) and Ochraria (yellow bloodwoods). Hill and Johnson's section Rufaria is monophyletic if Apteria and Fundoria are included. It is evident that, among the red bloodwoods, series are not monophyletic and several morphological characters result from convergent evolution. There was strong morphological and molecular evidence that the three species of red bloodwoods that occur in south-western Western Australia (series Gummiferae: C. calophylla and C. haematoxylon, and series Ficifoliae: C. ficifolia) form a monophyletic group, separate from the eastern C. gummifera (series Gummiferae), which is probably sister to the clade of all other red bloodwoods. Phylogenetic results supported recognition of new taxonomic categories within Corymbia, and these are formalised here.
A Taxonomic Revision of Melodinus (Apocynaceae) in Australia
Authors: Foster Paul I.
Published: November 2018

A taxonomic revision of Melodinus Forster & G. Forster in Australia is presented with generic and
specific descriptions, a key to species, illustrations, notes on typification with lectotypifications, distribution
and ecology, conservation status and local names. Four species, M. acutiflorus F. Muell.,
M. australis (F. Muell.) Pierre, M. bacellianus (F. Muell.) S . T. Blake and M. forbesii Fawc., are
recognised. M. forbesii is newly recorded from Australia.
Modified ratio estimators of population mean using linear combination of co-efficient of skewness and quartile deviation
Authors: Jeelani M. Iqbal , Maqbool S.
Published: November 2018

The present paper deals with the estimation of population mean of the study variable using the linear combination of known population values of coefficient of skewness and quartile deviation of auxiliary variable. Two modified ratio estimators for estimation of population mean of the study variable involving the above linear combinations are being used. Mean squared errors and biases up to the first degree of approximation are derived and compared with the proposed modified ratio estimators. The proposed modified ratio estimators perform better than the existing ratio estimators. The empirical study has been carried out in support of the results.
Nitrate import - export dynamics in groundwater interacting with surface-water in a wet-tropical environment
Authors: Rasiah V. , Armour J. D. , Cogle A. L. , Florentine S. K.
Published: November 2018

Solute import–export dynamics in groundwater (GW) systems interacting with surface-water are complex, particularly under farming systems receiving high fertiliser/pesticide inputs in high rainfall regions. We investigated whether any linkage existed between nitrate-N in: (i) leachate (LC) collected at ~1 m depth under banana (Musa) and that in GW, and (ii) GW and drain-water (DW). We also assessed the hazard/risk of the concentrations against the trigger values proposed for the sustainable health of different aquatic ecosystems. The LC, GW, and DW samples were collected at short intervals during 3 consecutive rainy seasons (January–July) from a ~300-ha banana farm in the wet tropical Tully River Catchment in north-east Queensland, Australia. Water samples were analysed for nitrate-N, dissolved organic carbon, and electrical conductivity.
The coefficients of variation, ranging from 13 to132%, obtained for solute concentrations in LC, GW, and DW indicated large within- and between-season temporal variations. The mean nitrate-N concentrations in LC, GW, and DW were 5320, 4135, and 1976 μg/L, respectively, and were orders of magnitude higher than the trigger values proposed for the sustainable health of most of the neighbouring aquatic ecosystems. Significant positive associations, with correlation coefficients ranging from 0.56 to 0.96, existed between rainfall received and LC volume collected, and between LC volume and solute concentration, including nitrate-N, in the LC. Similar associations existed between the solutes in (i) LC and GW and (ii) GW and DW. From these associations we conclude the unused/under-utilised nitrate that leached below the root-zone was imported into the GW by the percolating rainwater and was exported into the drain via GW base-flow discharge.
Soil biochemical changes at different wheat growth stages in response to conservation agriculture practices in a rice-wheat system of north-western India
Authors: Bera Tanushree , Sharma Sandeep , Thind H. S. , Sidhu H. S. , Jat M. L.
Published: November 2018

Intensive tillage, removal or burning of crop residues, limited organic manure use, declining irrigation water resources and scarcity of labour are the major causes of soil degradation and unsustainability of rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system (RWS) in South Asia.Resource conservation technologies (RCTs) such as zero tillage (ZT), dry direct seeded rice (DSR) and crop residues retained as mulch have shown promise to increase the productivity and profitability of RWS in South Asia. Effects of RCTs on soil biological parameters are unclear and contradictory. We evaluated the effects of conservation agriculture practices on changes in soil biochemical properties at different growth stages of wheat grown as the fifth crop in RWS. Twelve treatment combinations of tillage, crop establishment and crop residue management included four main plot treatments in rice: (1) conventional tillage (CT)-DSR,(2) ZT-DSR, (3) DTR, ZT machine transplanted rice and (4) PTR, conventional puddled transplanted rice. The three subplot treatments were: (i) CTW-R, CT wheat with both rice and wheat residues removed, (ii) ZTW-R, ZT wheat with residues of both the crops removed and (iii) ZTW+R, ZT wheat with rice residue retained as surface mulch in subsequent wheat. Irrespective of rice establishment methods, mean wheat grain yield under ZTW+R was 6% and 10% greater than CTW-R and ZTW-R respectively. Soil enzyme activities increased (5–18%) under ZTW+R compared with ZTW-R and CTW-R at different growth stages of wheat. The residual effect of rice establishment methods was significant on soil enzyme activities during wheat cropping, which were highest under ZT-DSR followed by CT-DSR, DTR and PTR. Soil organic carbon content in the 0–7.5 cm layer was significantly higher (7–9%) under the ZTW+R treatment compared with all the other treatments. Principal component analysis (PCA) identified three enzyme activities (dehydrogenase, fluorescein diacetate and phosphatase), and soil organic carbon content as the most sensitive indicators for assessing soil quality for RWS based on conservation agriculture. The PCA discriminated rice establishment systems with rice residue as surface mulch from rice establishment systems without rice residue and the maximum tillering stage from the other stages of wheat. The present study provided reliable biochemical indicators to monitor soil biological quality changes in response to conservation agriculture practices in RWS.
Pathways of phosphorus, nitrogen, and carbon movement over and through texturally differentiated soils, South Australia
Authors: Chittleborough D. J. , Cox J. W. , Stevens D. P.
Published: November 2018

One method for preventing the degradation of water supplies through
contamination with phosphorus (P), nitrate (NO3), and
dissolved organic carbon (DOC) is to restrict movement of these contaminants
from the catchment into water bodies. The purpose of the study was to quantify
and characterise the proportion of NO3, P, and DOC
moving from duplex soils by overland flow and through-flow on a sub-catchment
scale, and to characterise soil properties that influence their movement. Two
sites in the Adelaide Hills (South Australia) with contrasting duplex soils
were instrumented to collect overland flow and through-flow from the soils A
and B horizon. Each site contained 2 sub-catchments in close proximity.
Sub-catchments were well defined by the natural topography sloping from
hillcrest to a stream headwater. Soil type, especially the degree of texture
contrast, the macroporosity, and the proportion of clay in the B horizon, had
a large influence on the pathways of water, and therefore P, DOC, and
NO3 movement. Environmentally significant concentrations
of P (>0�1 mg/L) and NO3-N (>0�5 mg/L) moved
overland and through these soils in 1997. High DOC loads (25 mg/L), which
would also impact on water treatment costs, moved through some soils.
Significant loading of P moved through and over soils in both dissolved
(0�5 mg/L) and particulate (0�3 mg/L) forms.
Consequently, through-flow cannot be ignored as a contributor to P in streams
and both dissolved and particulate P must be measured under these conditions
to define the full impact of P. The findings from this research have
implications for research on catchment management to restrict DOC and nutrient
movement into waterways.
The forms of potassium and potassium adsorption in some virgin soils from south-western Australia
Authors: Pal Y. , Gilkes R. J. , Wong M. T. F.
Published: November 2018

This investigation was undertaken to determine the potassium (K) status and
adsorption behaviour of 227 samples from horizons of 41 representative virgin
soil profiles, extending from Geraldton in the north to the Great Southern
district of Western Australia. X-ray diffraction analysis of random powder of
whole soil indicated that quartz is the dominant mineral and some soils
contain significant amounts of feldspars. Clay mineralogy is dominated by
kaolinite but minor quantities of illite are present in some soils. Most
south-west Australian agricultural soils contain little available K:
NaHCO3-extractable K (NaHCO3-K,
median value 0·09 cmol K/kg, equivalent to 35 mg K/kg soil),
HNO3-extractable K (HNO3-K, median
value 0·30 cmol K/kg, equivalent to 117 mg K/kg soil), and
total K (XRF determined K, median value, 17 cmol K/kg, equivalent to 6630
mg K/kg soil). The proportion of water-soluble K
(H2O-K) ranges from 0 to 3·5% of total K,
0 to 76% of HNO3-K, and 0 to nearly 100%
of exchangeable K. Exchangeable K ranges from 0 to 100% (median value
37%) of HNO3-K. These are relatively high
proportions of H2O-K and exchangeable K compared with
soils from many other parts of the world. The amounts of all forms of K
variously increase or decrease downwards in the soil profile depending on both
clay content and mineralogy. The commonly assumed increase in K with clay
content alone is invalid.
The soils mostly have low-to-moderate values of K sorption capacity, ranging
from 5% to 67% (median value 14%) of added K (initially
4·1 mM K/L, equivalent to 4·1 cmol K/kg). otassium
sorption isotherms conform well to the Freundlich equation. The inability of
the Langmuir equation to describe the data may indicate that there are several
types of K sorption sites in these soils. The Gapon coefficient
KG varied widely from 0·04
to 29·8 (L/mol) ½ [median value 5·4 (L/mol)
½ ].
Career stages in wildland firefighting: implications for voice in risky situations
Authors: Lewis Alexis , Hall Troy E. , Black Anne
Published: November 2018

Avoidance of injury and death on the fireline may depend on firefighters voicing their concerns, but often this does not occur. Reasons for employee reticence identified in the literature include a perception of various personal costs or a belief that raising concerns is futile. Additionally, the social context may play a significant role. In a qualitative study using in‐depth interviews with 36 wildland firefighters in the US, we explored reasons firefighters do or do not voice concerns. Findings revealed two primary themes related to initiating voice (limits to environmental perception and social influence) that vary considerably depending on a firefighter’s career stage. Additionally, the tactics that firefighters use similarly vary with career stage. Rookies (novice firefighters) often lack the ability to discern and interpret environmental cues, rely on others to ensure safety, fear being stigmatised if they voice worries, and may believe no one will listen to them. Veteran firefighters – both mid‐career experienced firefighters and expert veterans in high‐experience leadership roles – are better able than rookies to perceive and describe risky situations and feel more confident to raise concerns. However, experienced firefighters still face social pressures that may lead them to remain silent. Expert veterans face fewer social pressures, but their roles can put them in situations where they are either complacent or distracted. Implications of these findings for firefighter training and fire leadership are discussed.