Thulium anomalies and rare earth element patterns in meteorites and Earth: Nebular fractionation and the nugget effect

This study reports the bulk rare earth element (REEs, La-Lu) compositions of 41 chondrites, including 32 falls and 9 finds from carbonaceous (CI, CM, CO and CV), enstatite (EH and EL) and ordinary (H, L and LL) groups, as well as 2 enstatite achondrites (aubrite). The CI-chondrite-normalized REE patterns and Eu anomalies in ordinary and enstatite chondrites show more scatter in more metamorphosed than in unequilibrated chondrites. This is due to parent-body redistribution of the REEs in various carrier phases during metamorphism. The dispersion in REE patterns of equilibrated ordinary chondrites is explained by the nugget effect associated with concentration of REEs in minor phosphate grains. Terrestrial rocks and samples from ordinary and enstatite chondrites display negative Tm anomalies of ~-4.5 % relative to ca chondrites. In contrast, CM, CO and CV (except Allende) show no significant Tm anomalies. Allende CV chondrite shows large excess Tm (~+10 %). These anomalies are similar to those found in group II refractory inclusions in meteorites but of much smaller magnitude. The presence of Tm anomalies in meteorites and terrestrial rocks suggests that either (i) the material in the inner part of the solar system was formed from a gas reservoir that had been depleted in refractory dust and carried positive Tm anomalies or (ii) CI chondrites are enriched in refractory dust and are not representative of solar composition for refractory elements. The observed Tm anomalies in ordinary and enstatite chondrites and terrestrial rocks, relative to carbonaceous chondrites, indicate that material akin to carbonaceous chondrites must have represented a small fraction of the constituents of the Earth.Comment: Geochimica et Cosmochimica Acta, in press, 58 pages, 6 tables, 14 figure

Molecular detection of prostate specific antigen in patients with prostate cancer or benign prostate hyperplasia the first investigation from Iran

Prostate cancer is the second common form of cancer in men. Detection of circulating Prostate Specific Antigen (PSA) transcripts has effectively been used for early diagnosis of prostate cancer cells. This investigation employed a reverse transcriptase polymerase chain reaction (RT-PCR) technique to distinguish the patients with either localized or metastatic prostate cancer (CaP) vs. Benign Prostate Hyperplasia (BPH) and control subjects, as compared with clinical and pathological records. With reservation of ethical issues, blood samples were collected from 60 cases. Based on pathological and clinical findings, 25 patients (20 with localized cancer, 5 with metastatic), 22 with BPH, and 13 healthy (including 3 females) subjects as negative controls, were selected from Shariati, Mehrad, Sina,, Khatam and Atie Hospitals in Tehran, Iran. RT-PCR for a 260 bp PSA transcript was then performed. Clinical and pathological records were used for the assessment and comparison of PSA RT-PCR results. None of the control subjects and BPH (with 7 exceptions) were found positive by RT-PCR (Relative specificity= 72.7). In patients with prostate cancer, 21 out of 25 were found PSA positive (Relative sensitivity= 83.4) and the remaining 3 have been shown to be PSA negative (Positive predictive value= 83.4). All of 5 metastatic patients (100) revealed PSA positive results. Our data reflects the clinical relevance and significance of RT-PCR results as assessed with clinical and pathological examinations. PSA RT-PCR might be used as a powerful means for diagnosis, even when either pathological or clinical findings are negative, and could be employed for further molecular epidemiology surveys

Microchimerism and Renal Transplantation: Doubt Still Persists

Objective: We sought to study microchimerism in a group of kidney transplant recipients. Materials and Methods: In this study, the peripheral blood microchimerism (PBM) after renal transplantation was retrospectively evaluated in 32 male-to-female recipients of living unrelated or cadaveric donor renal transplants. Using a nested polymerase chain reaction (PCR) amplification specific for SRY region of the Y chromosome, microchimerism was detected with a sensitivity of 1:1,000,000. Recipients were compared according to the presence of PBM, acute and chronic rejection episodes, type of allotransplant, recipient and donor age at transplantation, previous male labor or blood transfusion, allograft function (serum creatinine level), and body mass index. Results: Among 32 recipients, 7 (21.9) were positive for PBM upon multiple testing at various posttransplant times. All microchimeric recipients had received kidneys from living unrelated donors. No significant difference was observed with regard to other parameters. In addition the acute rejection rate in the microchimeric group was 3 (42) versus 4 (16) in the nonmicrochimeric recipients (not significant). Conclusion: Our results suggested better establishment of microchimerism after living donor kidney transplantation. However, doubt persists concerning the true effect of microchimerism after renal transplantation. It seems that microchimerism alone has no major protective role upon renal allograft survival. © 2007 Elsevier Inc. All rights reserved

Analysis of Short Tandem Repeats by Parallel DNA Threading

The majority of studies employing short tandem repeats (STRs) require investigation of several of these genetic markers. As such, we demonstrate the feasibility of the trinucleotide threading (TnT) approach for scalable analysis of STRs. The TnT method represents a parallel amplification alternative that addresses the obstacles associated with multiplex PCR. In this study, analysis of the STR fragments was performed with capillary gel electrophoresis; however, it should be possible to combine our approach with the massive 454 sequencing platform to considerably increase the number of targeted STRs

Twelve thousand years of dust: The Holocene global dust cycle constrained by natural archives

Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP paleodust datasets in the last two decades provided a target for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust dataset that moves on from the positive experience of DIRTMAP and takes into account new scientific challenges, by providing a concise and accessible dataset of temporally resolved records of dust mass accumulation rates and particle grain-size distributions. We consider data from ice cores, marine sediments, loess/paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows investigation of the potential, uncertainties and confidence level of dust mass accumulation rates reconstructions, and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 43 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggest that minimum dust fluxes are likely observed during the Early to mid-Holocene period (6000–8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize datasets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance and variability of the global dust cycle during the Holocene, with dust load ranging from 17.1 to 20.5 Tg between 2000 and 10 000 years ago, and a minimum in the Early to Mid-Holocene (6000–8000 years ago)

The survey of diversity, distribution and abundance of phytoplankton in the southern of Caspian Sea

The survey sampled during the fourth stage of the season was in 1387. Sampling in eight directions perpendicular (transect) to the beach and 480 samples was performed. In each transect from Astara to the Turkmen 5 stations at depths of 5, 10, 20, 50 and 100 m were selected for sampling. The total number of 191 species was identified; Bacillariophyta category species number was 97, equivalent to %50.8, category of Chlorophyta 28 species, equivalent to %14.7, category of Pyrrophyta 26 species, equivalent to 13.6 %, category of Cyanophyta 25 species, equivalent to 13.1% and category of Euglenophyta 15 species, equivalent to 7.9% of all species formed. Average abundance of phytoplankton was 27947500(SD=2465184) n/m^3. The average biomass was 125.51(SD=8.84) mg/m^3. Abundance and biomass in spring and summer, autumn and winter have been significant differences (p <0.05). The highest frequency was in winter, autumn, summer respectively and spring was (p <0.05) and the highest biomass in winter, fall, spring and summer was respectively (p <0.05). Bacillariophyta category has the highest abundance equal to 14390833 ± 16262.35 n/m^3 (mean ± standard error) were equivalent to %51.49 of the total abundance, Euglenophyta category has the least density equal to 109791 ± 16262.14 n/m^3 (mean ± standard error), which is equivalent to % 0.39 of total abundance were included. Also Pyrrophyta category has the highest biomass equal to 69.66 ± 5.53 mg/m^3 (standard error ± mean) were equivalent to %53.14 of the total biomass and Chlorophyta category with an average of 0.68 ± 0.11 mg/m^3 (mean ± standard error) have the lowest biomass, were equivalent to %0.54 of the total. Phytoplankton Categories in every season, with biomass and abundance have been different (p <0.05). Abundance and phytoplankton biomass in the upper layer and lower layer varies with depth of 50 meters (p <0.05). With distance from shore and depth increases, reducing the mean abundance and biomass were observed (p <0.05). The highest and lowest abundance of phytoplankton was observed at depths of 10 and 100 meters respectively. The maximum amount of phytoplankton biomass in surface areas of deep stations 20 m and the lowest biomass sampled at the deepest point of the station was 100 meters. Abundance and biomass of phytoplankton in the deep layers of the sample with significant difference (p<0.05). So that the highest abundance layers of 10 m, the surface layer of 5 m, 20 m, 50 m and 100 m, respectively(p <0.05), and the most biomass in the surface layers of 5 m, 20 m, 10 m, 50 and 100 meters, respectively (p <0.05). Abundance and biomass of phytoplankton in transects was significant difference (p <0.05). Most phytoplankton respectively transect Astara, Babolsar, Anzali Amirabad, Turkmen, Sefidrud, Noshahr, Branch was observed (p <0.05) and in terms of biomass, respectively transects Astara, Anzali, Sefidrud, Babolsar, Noushahr, Branch, Amirabad and Turkmen values were higher (p <0.05). Species diversity indexe (Shannon – Wiener) phytoplankton was equivalent to 2.92. Environmental conditions and nutrients in different seasons on these parameters influenced the way that species diversity was lowest in summer and in autumn, winter, and spring, respectively, species diversity increased

Highly-multiplexed barcode sequencing: an efficient method for parallel analysis of pooled samples

Next-generation sequencing has proven an extremely effective technology for molecular counting applications where the number of sequence reads provides a digital readout for RNA-seq, ChIP-seq, Tn-seq and other applications. The extremely large number of sequence reads that can be obtained per run permits the analysis of increasingly complex samples. For lower complexity samples, however, a point of diminishing returns is reached when the number of counts per sequence results in oversampling with no increase in data quality. A solution to making next-generation sequencing as efficient and affordable as possible involves assaying multiple samples in a single run. Here, we report the successful 96-plexing of complex pools of DNA barcoded yeast mutants and show that such ‘Bar-seq’ assessment of these samples is comparable with data provided by barcode microarrays, the current benchmark for this application. The cost reduction and increased throughput permitted by highly multiplexed sequencing will greatly expand the scope of chemogenomics assays and, equally importantly, the approach is suitable for other sequence counting applications that could benefit from massive parallelization

The risk factors of prostate cancer: A multicentric case-control study in Iran

Prostate cancer (PC), in Iran, is the third most frequently diagnosed visceral cancer among men and the seventh most common underlying cause of cancer mortality. We evaluated the relation between speculated factors and PC risk using data from a multicentric case-control study conducted in Iran from 2005 to 2007 on 130 cases of incident, clinicopathologically confirmed PC, and 75 controls admitted to the same network of hospitals without any malignant disease. Odds ratios(OR) and corresponding 95 confidence intervals (CIs) were estimated using conditional logistic regression models. The risk of PC was increased with aging (OR: 5.35, 95 CI: 2.17-13.19; P<0.0001), and with the number of sexual intercourse �2 times/week (OR: 3.14, 95 CI: 1.2-8.2; P=0.02). One unit elevation in serum estradiol and testosterone concentration was related to increase (OR: 1.04, 95 CI: 1.01-1.06; P=0.006) and decrease (OR: 0.79; 95 CI: 0.64-0.96; P=0.02) of PC risk, respectively. Cases were less likely to have a history of diabetes (OR: 0.34, 95 CI: 0.12-0.98; P=0.04). Increasing in dietary consumption of lycopene and fat was associated with declined (OR: 0.45, 95 CI: 0.09-2.12) and increased (OR: 2.38, 95 CI: 0.29-19.4) PC development, respectively. Other factors including educational level, marriage status, dietary meat consumption, vasectomy and smoking have not been shown to affect PC risk in the Iranian population. Ourstudy adds further information on the potential risk factors of PC and is the first epidemiologic report from Iran. However, justification of these results requires more well-designed studies with a larger number of participants

Dynamic Control of Nanoprecipitation in a Nanopipette

Studying the earliest stages of precipitation at the nanoscale is technically challenging but quite valuable as such phenomena reflect important processes such as crystallization and biomineralization. Using a quartz nanopipette as a nanoreactor, we induced precipitation of an insoluble salt to generate oscillating current blockades. The reversible process can be used to measure both kinetics of precipitation and relative size of the resulting nanoparticles. Counter ions for the highly water-insoluble salt zinc phosphate were separated by the pore of a nanopipette and a potential applied to cause ion migration to the interface. By analyzing the kinetics of pore blockage, two distinct mechanisms were identified: a slower process due to precipitation from solution, and a faster process attributed to voltage-driven migration of a trapped precipitate. We discuss the potential of these techniques in studying precipitation dynamics, trapping particles within a nanoreactor, and electrical sensors based on nanoprecipitation