Role of in Situ Natural Organic Matter in Mobilizing As during Microbial Reduction of FeIII-Mineral-Bearing Aquifer Sediments from Hanoi (Vietnam).

Natural organic matter (NOM) can contribute to arsenic (As) mobilization as an electron donor for microbially-mediated reductive dissolution of As-bearing Fe(III) (oxyhydr)oxides. However, to investigate this process, instead of using NOM, most laboratory studies used simple fatty acids or sugars, often at relatively high concentrations. To investigate the role of relevant C sources, we therefore extracted in situ NOM from the upper aquitard (clayey silt) and lower sandy aquifer sediments in Van Phuc (Hanoi area, Vietnam), characterized its composition, and used 100-day microcosm experiments to determine the effect of in situ OM on Fe(III) mineral reduction, As mobilization, and microbial community composition. We found that OM extracted from the clayey silt (OMC) aquitard resembles young, not fully degraded plant-related material, while OM from the sandy sediments (OMS) is more bioavailable and related to microbial biomass. Although all microcosms were amended with the same amount of C (12 mg C/L), the extent of Fe(III) reduction after 100 days was the highest with acetate/lactate (43 ± 3.5% of total Fe present in the sediments) followed by OMS (28 ± 0.3%) and OMC (19 ± 0.8%). Initial Fe(III) reduction rates were also higher with acetate/lactate (0.53 mg Fe(II) in 6 days) than with OMS and OMC (0.18 and 0.08 mg Fe(II) in 6 days, respectively). Although initially more dissolved As was detected in the acetate/lactate setups, after 100 days, higher concentrations of As (8.3 ± 0.3 and 8.8 ± 0.8 µg As/L) were reached in OMC and OMS, respectively, compared to acetate/lactate-amended setups (6.3 ± 0.7 µg As/L). 16S rRNA amplicon sequence analyses revealed that acetate/lactate mainly enriched Geobacter, while in situ OM supported growth and activity of a more diverse microbial community. Our results suggest that although the in situ NOM is less efficient in stimulating microbial Fe(III) reduction than highly bioavailable acetate/lactate, it ultimately has the potential to mobilize the same amount or even more As.

A pyramid of loci for partial resistance to Fusarium solani f. sp. glycines maintains Myo-inositol-1-phosphate synthase expression in soybean roots.

Myo-inositol 1-phosphate synthase (MIPS; EC 5.5.1.4) converts glucose 6-phosphate to myo-inositol 1-phosphate in the presence of NAD(+). It catalyzes the first step in the synthesis of myo-inositol and pinitol, and is a rate limiting step in the de novo biosynthesis of inositol in eukaryotes. Therefore, MIPS is involved in biotic and abiotic stress via Ca(2+) signalling. Seedlings of four soybean genotypes were inoculated with Fusarium solani f. sp. glycines, the causative agent of sudden death syndrome (SDS), and differentially abundant mRNAs were identified by differential display. The genotypes carried either zero, two, four or six alleles of the quantitative trait loci (QTLs) that control resistance to SDS in an additive manner. The mRNA abundance of MIPS did not decrease following inoculation in a recombinant inbred line (RIL 23) containing all six resistance alleles of the QTLs conferring resistance to SDS of soybean. However, the abundance of MIPS mRNA was decreased in genotypes containing four, two or no resistance alleles. The specific activity of the MIPS enzyme in vitro followed the same pattern across genotypes. The IP(3) content in the inoculated roots of genotypes with two, four or six resistance alleles were higher compared to the non-inoculated root. The results suggests that a non-additive effect on transcription and translation of MIPS is established in RIL 23 roots by pyramiding six QTLs for resistance to SDS. A role of MIPS in the partial resistance or response of soybean roots to F. solani infection is suggested.

Analysis of school injuries resulting in emergency department or hospital admission.

OBJECTIVE: To describe the epidemiology of school injuries resulting in emergency department (ED) visits, hospital admission, or death. METHODS: Utah statewide school injuries from 1992 to 1996 were probabilistically linked to statewide ED records (1996 only), inpatient hospital records (1992-1996), and death certificate records (1992-1996). RESULTS: There were 43,881 school injuries for the years 1992 through 1996. In 1996, 1,534 of 6,354 total school injuries (17.5%) resulted in ED evaluation. Between 1992 and 1996, 354 school injuries (0.8%) necessitated hospital admission. The overall rates of school injuries (per 1,000 students) of primary (kindergarten-grade 6) and secondary (grades 7-12) school students requiring ED evaluation were 3.29 and 3.28, respectively; for hospital admission, 0.165 and 0.139. Abbreviated Injury Scale-1990 (AIS-90) regions identified in ED patients were the upper extremity (39.2%), face (20.8%), and lower extremity (17.1%), while AIS regions among inpatients were lower extremity (29.1%), upper extremity (26.6%), and head (22.6%). There were a total of 1,123 hospital days, and total charges of $2.16 million. The ED charges totaled $545,000. Median length of hospital stay was 1 day, and median hospital charge was $3,080. There were four fatalities. CONCLUSIONS: This study emphasizes the significance of school injuries and the need for interventions to prevent these injuries

Direct evidence for a ruthenium(IV) oxo complex-mediated oxidation of a hydroxamic acid in the presence of phosphine oxide donors.

Ruthenium(II) complexes can be used to oxidise N-Boc hydroxylamine the the presence of tert-butylhydroperoxide to the corresponding nitroso dienophile, which is trapped using cyclohexa-1,3-diene as the hetero-Diels-Alder adduct; direct evidence has been obtained for the intervention of a triphenylphosphine oxide-stabilised ruthenium(IV) oxocomplex as the catalytically active species.

Injuries sustained by students in shop class.

OBJECTIVE: Injuries in the school environment are a serious public health problem. Injuries occurring within the school shop class are a part of this problem that has received little to no attention. The purpose of our study was to describe the epidemiology of shop class injuries in Utah public schools for the years 1992-1996. METHODS: Utah statewide grades 7 through 12 school injury data for 1992-1996 were used. The data were generated from a standardized Student Injury Report form completed by school personnel immediately after the occurrence of an injury on school premises that: 1) caused loss of at least one half of a day of school; and/or 2) warranted medical attention and treatment. Shop injuries were defined as injuries that occurred in industrial art classes, vocational educational classes, or automotive classes. To determine the medical outcome and hospital charges associated with shop class injuries, we linked the Student Injury Report database to Utah statewide emergency department (ED) records (available for 1996 only), and to Utah statewide hospital inpatient discharge records (1992-1996). RESULTS: During 1992-1996, 14 133 students in grades 7 through 12 were injured at school, of which 1008 (7.1%) were injured during a shop class. The majority (88. 4%) of shop injuries involved equipment use. Equipment was misused in 37.9% and malfunctioned in 3.5% of the incidents. The leading injuries reported for shop equipment were lacerations (70.9%), burns (6.0%), and abrasions (4.6%), whereas the leading for nonequipment injuries were lacerations (45.4%), fractures (9.2%), and pain/tenderness (6.7%). In 1996, 167 students were injured in a shop class and 45 (26.9%) visited an ED as a result of the shop injury. Equipment was a factor in 88.9% of the shop injuries admitted to the ED. Table saws (15.0%), other saws (15.0%), and band saws (12.5%) were involved in nearly one half of the equipment injuries. Equipment was misused in 44.7% and malfunctioned in 10.5% of the incidents resulting in an ED visit. The majority (64.4%) of students sustained an open wound injury. The total ED charges were $16 571. For 1992-1996, 1008 students were injured in a shop class, 7 (.7%) required inpatient hospital care. Six of the students were injured using a table saw and 1 sustained injuries attributable to automotive cleaning fluid. Equipment was used improperly in 4 of the table saw injuries. Six of the students sustained hand injuries, with 3 suffering a traumatic amputation of a finger or thumb. The total inpatient charges were $26 747. CONCLUSION: School shop injuries have a great impact on students, their families, and schools because of the loss of productivity for the student and the financial impact. Many of the injuries are preventable. These findings stress the need for school administrators, teachers, and students to develop and improve safety policies and practices in school shop classes. In addition, the findings may provide useful information to pediatricians and enable them to better inform patients of risks in school shop classes.

Enantioselective hydrogenation of olefins with phosphinooxazoline-iridium catalysts.

Cationic iridium complexes with chiral phosphinooxazoline ligands are efficient catalysts for the enantioselective hydrogenation of olefins. The complexes are readily prepared, air-stable, and easy to handle. In contrast to chiral rhodium- and ruthenium-phosphine catalysts, they do not require the presence of a polar coordinating group near the C=C bond. In the hydrogenation of unfunctionalized trisubstituted 1,2-diaryl-olefins, high enantioselectivities of >95% ee with full conversion and turnover frequencies of >7,000 h-1 can be achieved, using 0.1 mol% of catalyst with tetrakis[3, 5-bis(trifluoromethyl)phenyl]borate (TFPB or BARF) as the counterion. The corresponding hexafluorophosphate or tetrafluoroborate salts give low conversion due to deactivation of the catalyst during the reaction. Substrates with polar substituents such as allylic alcohols, on the other hand, afford better results with the hexafluorophosphate salts.

Effect of sex grouping during growth on 5α-androstenone development in boars at three commercial slaughter weights.

Groups of boars and gilts were grown in either single-sex or mixed groups to slaughter weights of 81, 93 or 110 kg liveweight to examine the effects of sex grouping on growth performance, animal behaviour and the development of androstenone-taint in the males. Results confirmed the well known growth advantages of entire males and showed that no husbandry problems of any significance were incurred with the boars and gilts raised together, particularly in those groups slaughtered before reaching 100 kg liveweight. In pigs taken to heavier weights, boars were successfully reared with gilts without incurring management problems, although growth performance was slightly poorer for the boar/gilt groups compared with mixed castrates and gilts, and some of the boars had high concentrations of androstenone in the fat. Thus, for pigs intended for slaughter at heavy commercial weight, the evidence suggests that split-sex rearing (and therefore feeding) should be practised. No useful correlations of androstenone concentration in fat were found with thickness of backfat, age, carcass weight or liveweight at slaughter.

Accuracy and value of the Hemoccult test in symptomatic patients.

Hemoccult faecal occult blood testing is widely advocated as a screening test for colorectal cancer but few studies have shown its correlation with conventional methods of investigation for colorectal disease. In a prospective study of 802 symptomatic patients with suspected colorectal disease there was good patient compliance (92.5%) and a high specificity for colorectal cancer (85.4%). The false positive rate was 8.6% (12 of 140 patients with positive results), and while the test result was positive in 22 of 26 colonic cancers the false negative rate for rectal cancer (45.4%) should not detract from its value as a screening test if proper digital anorectal and proctosigmoidoscopic examination are widely practised. A positive Hemoccult test result is a useful indicator for the need to proceed to full colorectal investigation, including colonoscopy.

T cell leukaemia in the rat: stable marker chromosome in leukaemic cells.

The karyotype of a transplantable T cell leukaemia which arose originally in a PVG strain rat undergoing chronic internal beta irradiation of the spleen was examined and a marker chromosome was found. Although the leukaemia progressively became more acute during 4 years of continuous passage the marker did not change. Cytogenetic analysis of normal rats given an acute exposure to external irradiation revealed, among other abnormalities, a marked of the same morphology indicating that the original marker was probably radiation induced. This is the first description of a stable marker chromosome in an experimental animal leukaemia.