A new role for sulfur in arsenic cycling

Sulfur and arsenic often coexist in the environment and share similar microbial redox transformations. We examined the effects of sulfide on aerobic arsenite oxidation in alkaline lake water samples and in laboratory enrichment cultures. Significant arsenite oxidation occurred only in treatments with bacteria present, and production of arsenate was greatly enhanced by the addition of sulfide or thiosulfate. IC-ICP-MS analysis of samples showed that mono- and dithioarsenate formed in arsenite + sulfide amended lake water. Our data indicate that these two thioarsenic compounds are fairly stable in sterile alkaline solutions, but are transformed predominantly to arsenate when bacteria are present. Enrichment culture experiments suggest that sulfur-oxidizing bacteria use free or arsenic-bound sulfur as a growth substrate and directly or indirectly transform arsenite and thioarsenates to arsenate during growth. Increases in cell density resulted in more rapid conversion of arsenite and thioarsenates. The rate and extent of these processes appearto be controlled bythe concentration of bacteria and the ratio of reduced sulfur to arsenite present. Sulfur-driven arsenite oxidation and microbial thioarsenate transformation may be important biogeochemical processes in the arsenic cycle of our study site (Mono Lake, CA, USA) and other alkaline environments as well.     

State laws on youth access to tobacco in the United States: measuring their extensiveness with a new rating system

OBJECTIVE: To develop and implement a rating system evaluating the extensiveness of state laws restricting youth access to tobacco. DESIGN: State laws on youth access to tobacco were analysed and assigned ratings on nine items. Six items addressed specific tobacco-control provisions, and three related to enforcement provisions. For each item, a target was specified reflecting public health objectives. Achieving the target resulted in a rating of +4 points; for three items, a rating of +5 was possible if the target was exceeded. Criteria for lower ratings were established for situations when the target was not met. SETTING: United States. RESULTS: State scores (sum of the ratings across all nine items) ranged from 0-18 in 1993, 2-21 in 1994, and 1-21 in 1995 and 1996, out of a possible total of 39. The average score across states was 7.2 in 1993, 7.9 in 1994, 8.2 in 1995, and 9.0 in 1996. The overall mean rating (per item) was 0.80 in 1993, 0.88 in 1994, 0.91 in 1995, and 1.00 in 1996, on a scale where 4.0 indicates that the target goals (per item) were met. From 1993 to 1996, scores increased for 20 states, decreased for one state, and remained unchanged for the others. The number of states for which state preemption of local tobacco regulation was a factor doubled from 10 states in 1993 to 20 states in 1996. CONCLUSIONS: Although all states have laws addressing youth access to tobacco, this analysis reveals that, as of the end of 1996, the progress towards meeting health policy targets is slow, and state legislation that preempts local tobacco regulation is becoming more common.     

Estimation of lamb carcass composition from measurements of the speed of ultrasound in the soft tissues of live animals and carcasses

The application of the velocity of sound (VOS) technique to lamb carcasses in a previous study (Fisher & Page, 1986) measured composition at a hind limb and neck site but was not as precise as fat scores in predicting lean proportion. This study examines VOS measurements made at sites in the hind limbs and along the vertebral column in live sheep and carcasses. A group (A) comprising five breeds of males and females (n = 61) and a sub-group (B) of Scottish Blackface castrated males (n = 34) were studied, and the reciprocal velocity of ultrasound (RV) was measured on the live sheep immediately behind the shoulder and over the last rib using a fixed-distance transducer assembly operating at 5 MHz, and in the hind limbs at 2·25 MHz using the apparatus described by Miles et al. (1984). Corresponding measurements were made on the carcasses which were classified by a Meat and Livestock Commission fatstock officer and then dissected. Standard deviations of lean proportion were 4·48% (A) and 3·39% (B). The residual standard deviations (rsds) for groups A and B respectively were obtained using the following predictors: live mass (LM) 4·27% and 2·96%; LM + breed (B) 3·08% (group A only); LM + mean RV 2·36% and 2·07%; LM + B + mean RV 1·99% (group A only). Using carcass measurements: carcass mass (CM) 4·25% and 2·90%; CM + MLC fat score 2·99% and 2·12%; CM + RV last rib 2·89% and 2·02%. These data show that VOS measurements through dorsal sites of live sheep provide encouragingly precise estimates of carcass lean proportion. For carcasses, dorsal sites provide a less precise estimate of carcass lean but when carcass mass is included in multiple regression the precision of the correlation is comparable with that of multiple regression of fat score with carcass mass.     

Effects of variation in streamflow and channel structure on smallmouth bass habitat in an alluvial stream

We evaluated the effects of streamflow‐related changes in channel shape and morphology on the quality, quantity, availability and spatial distribution of young‐of‐year and adult smallmouth bass Micropterus dolomieu habitat in an alluvial stream, the Baron Fork of the Illinois River, Oklahoma. We developed Habitat Suitability Criteria (HSC) for young‐of‐year and adult smallmouth bass to assess changes in available smallmouth bass habitat between years, and compare predicted smallmouth bass Weighted Usable Area (WUA) with observed WUA measured the following year. Following flood events between 1999 and 2000, including a record flood, changes in transect cross‐sectional area ranged from 62.5% to 93.5% and channel mesohabitat overlap ranged from 29.5% to 67.0% in study three study reaches. Using Physical HABitat SIMulation (PHABSIM) system analysis, we found that both young‐of‐year and adult smallmouth bass habitat were differentially affected by intra‐ and inter‐annual streamflow fluctuations. Maximum WUA for young‐of‐year and adults occurred at streamflows of 1.8 and 2.3 m³ s^?1, respectively, and WUA declined sharply for both groups at lower streamflows. For most microhabitat variables, habitat availability was similar between years. Habitat suitability criteria developed in 1999 corresponded well with observed fish locations in 2000 for adult smallmouth bass but not for young‐of‐year fish. Our findings suggest that annual variation in habitat availability affects the predictive ability of habitat models for young‐of‐year smallmouth bass more than for adult smallmouth bass. Furthermore, our results showed that despite the dynamic nature of the gravel‐dominated, alluvial Baron Fork, HSC for smallmouth bass were consistent and transferable between years. Published in 2008 by John Wiley & Sons, Ltd.     

Telemetry Application in the Glass Industry

Telemetry technique and presently available equipment may be utilized to optimize information retrieval speed and to minimize the total cost of information. An example of equipment is presented with basic theory of operation. Specific applications are discussed in the areas of pressure, temperature, and strain measurement. Technique is reviewed in terms of antenna placement and heat shielding of the telemetry package. By use of the systems approach to information retrieval, telemetry technique can be of value to the glass industry where other methods of measurement are not optimum or applicable.     

Investigation of wear of knee prostheses in a new displacement/force-controlled simulator

The performance of two knee simulators designed by ProSim (Manchester, UK) was evaluated by comparison of the wear seen in the press-fit condylar (PFC) Sigma (DePuy) knee prosthesis. Twelve specimens of the same design and manufacturing specification, were subjected to a wear test of 2 x 10(6) cycles duration using bovine serum as a lubricant. The anterior/posterior displacement and internal/external rotation inputs were based on the kinematics of the natural knee. International Standards Organization (ISO) standards were used for the flexion and axial load. The wear rates and wear scar areas were compared across all stations. The mean wear rates found were 17.6+/-5 mm3/10(6) cycles for stations 1 to 6 and 19.6+/-4 mm3/10(6) cycles for stations 7 to 12, resulting in an overall mean wear rate of 18.1+/-3 mm3/10(6) cycles. The differences between the two simulators were not significant. The average wear scar area seen on inserts from stations I to 6 was calculated at 32.4+/-1 per cent of the intended articulating surface. Similarly on stations 7 to 12 the average wear scar area was 30.7+/-3 per cent. The wear scars seen were a good physiological representation of those found from clinical explant data. This study has shown good repeatability from the simulator, both within and between the simulators.     

A microwave photonic phase-shifter based on wavelength conversion in a DFB laser

We propose and demonstrate a microwave photonic phase-shifter using a distributed-feedback laser-wavelength converter. Through carrier competition in the laser, information is passed from the input signal to the lasing mode. The frequency response of this conversion mechanism follows the intrinsic modulation response of the laser, which exhibits a large phase change near the relaxation frequency. Through current-control of the relaxation frequency, the phase of the wavelength-converted microwave output can be varied by more than 135/spl deg/ over a bandwidth of 1.8GHz. We further identify an operating regime that exhibits a large discrete phase shift of 114/spl deg/ at 3 GHz with negligible change in power.     

Replacing "who is the client?" with a different ethical question.

The familiar question, Who is the client? has become a distraction from more important ethical questions. By requiring a singular answer, the question obscures the fact that psychologists have ethical obligations toward every party in a case, no matter how many or how named. Making the question plural is not a sufficient solution, because identifying the client(s) should not be treated as an end in itself; it is simply a means of clarifying the nature of the relationship(s) and understanding the accompanying ethical obligations. After exploring the underlying implications for informed consent, confidentiality, and other ethical duties, the author suggests that psychologists adopt an alternative ethical question: What are my ethical responsibilities to each of the parties in this case? Finally, a case example illustrates the fact that the old question has several different meanings (and therefore different answers), depending upon whether it is asked as an ethical, clinical, legal, or reimbursement question. The proposed new question avoids such confusion because it is easily identifiable as an ethical question and its meaning is clear. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The number of single nucleotide polymorphisms and on-farm data required for whole-herd parentage testing in dairy cattle herds

New platforms utilizing single nucleotide polymorphisms (SNP) offer operational advantages over the conventional microsatellite-based ones, making them a promising alternative for parentage exclusion. Through simulation and empirical data, a 40-SNP panel (where the minor allele frequency was 0.35 on average) was shown to be a comparable or better diagnostic tool than the current 14-microsatellite panel that is used to parentage test New Zealand dairy animals. The 40 SNP alone did not have sufficient power of exclusion to match more than 75% of the progeny to the correct sire and dam. Utilizing mating records and grouping progeny and dams by birth and calving dates, respectively, decreased the number of sire-dam combinations that each progeny was tested against and dramatically increased the utility of the SNP. These results highlight the importance of combining genotypes with on-farm data to maximize the ability to assign parentage in the New Zealand dairy herd.