Automated SEM analysis of particles in Hanford tank waste.

Multiple bench-scale filtration campaigns of Hanford tank waste supernatant on a backpulseable dead-end filtration skid have provided greater insight into the solids that cause fouling and reduce filter performance. The solids collected during each campaign were concentrated from the backpulse solutions and examined using automated particle analysis (APA) methods with scanning electron microscopy and X-ray energy dispersive spectroscopy to categorize particle types and their morphological characteristics. We show that with APA, thousands of particles can be analyzed to provide accurate insight into the phases that may be impacting filter performance.

Examining the Predictive Validity of the Grit Scale-Short (Grit-S) Using Domain-General and Domain-Specific Approaches With Student-Athletes.

This paper contributes to the debate as to whether grit is best conceptualized and measured as a domain-specific or domain-general construct. In the field of sport psychology, grit has traditionally been conceptualized and measured as a domain-general construct, with the majority of studies using the Grit Scale-Short (Grit-S: Duckworth and Quinn, 2009) to assess grit and its relationships with an array of personality-, performance-, and health-related outcomes. To date, no studies have compared the predictive validity of domain-general and domain-specific versions of the Grit-S with athletes who operate in different achievement settings. In a sample of United Kingdom student-athletes (N = 326, 214 males, 112 females; Mage = 19.55 years, SD = 1.48 years), we examined the degree to which a domain-general version and two domain-specific versions of the Grit-S accounted for variance in two criterion variables that were either situated in an academic context (i.e., emotional exhaustion) or a sport context (i.e., competitive level). Results obtained from a series of hierarchical multiple regression analyses indicated that an academic-version of the Grit-S explained unique variance in academic emotional exhaustion beyond the variance explained by the domain-general version of the scale, and a sport-version of the Grit-S explained unique variance in competitive level beyond the variance explained by the domain-general version. Results support the adoption of domain-specific approaches to measure grit in specific achievement contexts. Our findings highlight the need for researchers to carefully consider the measurement approaches they adopt when studying grit in individuals who operate across different achievement settings.

Female Athletes' Experiences of Positive Growth Following Deselection in Sport.

The purpose of this study was to explore female athletes' experiences of positive growth following deselection from provincial sport teams. Interviews were conducted with 18 women (Mage = 22.45 years, SD = 1.38) who were deselected from provincial soccer, ice hockey, and volleyball teams as adolescents. Interpretative phenomenological analysis methodology was used. The analysis was guided by Tedeschi and Calhoun's model of posttraumatic growth. Results showed that participants questioned their identity and ability as athletes following deselection. Growth was a gradual process that unfolded over several years, experienced through a greater appreciation of the role of sport in the participants' lives and sport becoming a priority, an enhanced sense of personal strength, developing closer social relationships, and a recognition of new and other opportunities. These findings show that cognitive processes and social relationships are critical components in the process of positive growth.

Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy.

Background: In patients with ischaemic left ventricular dysfunction, coronary artery bypass surgery (CABG) may decrease mortality, but it is not known whether CABG improves functional capacity. Objective: To determine whether CABG compared with medical therapy alone (MED) increases 6 min walk distance in patients with ischaemic left ventricular dysfunction and coronary artery disease amenable to revascularisation. Methods: The Surgical Treatment in Ischemic Heart disease trial randomised 1212 patients with ischaemic left ventricular dysfunction to CABG or MED. A 6 min walk distance test was performed both at baseline and at least one follow-up assessment at 4, 12, 24 and/or 36 months in 409 patients randomised to CABG and 466 to MED. Change in 6 min walk distance between baseline and follow-up were compared by treatment allocation. Results: 6 min walk distance at baseline for CABG was mean 340±117 m and for MED 339±118 m. Change in walk distance from baseline was similar for CABG and MED groups at 4 months (mean +38 vs +28 m), 12 months (+47 vs +36 m), 24 months (+31 vs +34 m) and 36 months (-7 vs +7 m), P>0.10 for all. Change in walk distance between CABG and MED groups over all assessments was also similar after adjusting for covariates and imputation for missing values (+8 m, 95% CI -7 to 23 m, P=0.29). Results were consistent for subgroups defined by angina, New York Heart Association class ≥3, left ventricular ejection fraction, baseline walk distance and geographic region. Conclusion: In patients with ischaemic left ventricular dysfunction CABG compared with MED alone is known to reduce mortality but is unlikely to result in a clinically significant improvement in functional capacity. Trial registration number: NCT00023595.

Patient satisfaction with task shifting of antiretroviral services in Ethiopia: implications for universal health coverage.

Formalized task shifting structures have been used to rapidly scale up antiretroviral service delivery to underserved populations in several countries, and may be a promising mechanism for accomplishing universal health coverage. However, studies evaluating the quality of service delivery through task shifting have largely ignored the patient perspective, focusing on health outcomes and acceptability to health care providers and regulatory bodies, despite studies worldwide that have shown the significance of patient satisfaction as an indicator of quality. This study aimed to measure patient satisfaction with task shifting of antiretroviral services in hospitals and health centres in four regions of Ethiopia. This cross-sectional study used data collected from a time-motion study of patient services paired with 665 patient exit interviews in a stratified random sample of antiretroviral therapy clinics in 21 hospitals and 40 health centres in 2012. Data were analyzed using f-tests across provider types, and multivariate logistic regression to identify determinants of patient satisfaction. Most (528 of 665) patients were satisfied or somewhat satisfied with the services received, but patients who received services from nurses and health officers were significantly more likely to report satisfaction than those who received services from doctors [odds ratio (OR) 0.26, P < 0.01]. Investments in the health facility were associated with higher satisfaction (OR 1.07, P < 0.01), while costs to patients of over 120 birr were associated with lower satisfaction (OR 0.14, P < 0.05). This study showed high levels of patient satisfaction with task shifting in Ethiopia. The evidence generated by this study complements previous biomedical and health care provider/regulatory acceptability studies to support the inclusion of task shifting as a mechanism for scaling-up health services to achieve universal health coverage, particularly for underserved areas facing severe health worker shortages.

A longitudinal study of syringe acquisition by Puerto Rican injection drug users in New York and Puerto Rico: implications for syringe exchange and distribution programs.

Increasing access to sterile syringes and new drug preparation materials is an effective means of reducing HIV transmission among injection drug users (IDUs), and a fundamental component of harm reduction ideology. The purpose of this study is to examine changes during a three-year period in syringe acquisition by street-recruited Puerto Rican IDUs characterized by frequent drug injection and high HIV seroprevalence. At baseline (1998-1999) and 36-month follow-up, 103 IDUs recruited in East Harlem, New York (NY), and 135 from Bayamón, Puerto Rico (PR) were surveyed about syringe sources and HIV risk behaviors in the prior 30 days. A majority of participants in both sites were male (NY 78.6%, PR 84.4%), were born in Puerto Rico (NY 59.2%, PR 87.4%), and had not completed high school (NY 56.3%, PR 51.9%). Compared to PR IDUs at follow-up, NY IDUs injected less (3.4 vs. 7.0 times/day, p < .001), and re-used syringes less (3.1 vs. 8.0 times, p < .001). Between baseline and follow-up, in NY the proportion of syringes from syringe exchange programs (SEPs) increased from 54.2% to 72.9% (p = .001); syringes from pharmacies did not increase significantly (0.2% to 2.5%, p = .095). In PR, the proportions of syringes from major sources did not change significantly: private sellers (50.9% to 50.9%, p = .996); pharmacies (18.6% to 19.0%, p = .867); SEP (12.8% to 14.4%, p = .585). The study indicates that NY SEPs became more dominant, while NY pharmacies remained a minor source even though a law enacted in 2001 legalized syringe purchases without prescription. Private sellers in PR remained the dominant and most expensive source. The only source of free syringes, the SEP, permitted more syringes to be exchanged but the increase was not statistically significant. Implications for syringe exchange and distribution programs are discussed.

Injecting shared drugs: an observational study of the process of drug acquisition, preparation, and injection by Puerto Rican drug users.

The practice of injecting shared drugs, in which drug users prepare, divide and inject portions of a drug solution, is a means of transmitting HIV, HCV, and other blood-borne pathogens. This study examined the process of injecting shared drugs among drug users in San Juan, Puerto Rico, through detailed observations of 25 episodes of the injection of shared drugs, and by informal interviewing of episode participants. The ways in which price and packaging of drugs, access to drug preparation materials, and social and economic relations between drug-sharing "partners" influence the process of injecting shared drugs are explored. Because differential power relations, and in turn, injection drug users' exposure to HIV and HCV, are apparent in some drug-sharing partnerships, a key objective of this study was to extend our understanding of contributions or "investments" made by different drug-sharing partners, the benefits and costs that different partners experience, and the extent to which IDUs assume different partner roles. The findings of this small, in-depth qualitative study provide insight into drug users' motivations for injecting shared drugs, and suggest reasons why certain standardized, countrywide HIV/HCV intervention efforts have not been entirely successful in preventing the devastating illnesses that disproportionately affect injection drug users.

High temperature gate control of quantum well spin memory.

Time-resolved optical measurements in (110)-oriented GaAs/AlGaAs quantum wells show a tenfold increase of the spin-relaxation rate as a function of applied electric field from 20 to 80 kV cm(-1) at 170 K and indicate a similar variation at 300 K, in agreement with calculations based on the Rashba effect. Spin relaxation is almost field independent below 20 kV cm(-1) reflecting quantum well interface asymmetry. The results indicate the achievability of a voltage-gateable spin-memory time longer than 3 ns simultaneously with a high electron mobility.

Puerto Rican drug users experiences of physical and sexual abuse: comparisons based on sexual identities.

This study integrates the results of quantitative and qualitative methods to elucidate the association between sexual identity and physical and sexual abuse among Puerto Rican drug users. A structured questionnaire was administered to 800 subjects in New York and 399 in Puerto Rico. A total of 93 subjects (7.9%) self-identified as homosexual or bisexual. Gay males were significantly more likely than heterosexual males to report first occurrence of physical abuse by a family member in childhood. Both gay and bisexual males were more likely than their heterosexual counterparts to report first experiencing unwanted sex in childhood and intimate partner physical abuse later in life. Lesbians were more likely than female heterosexuals to report unwanted sex in childhood. Qualitative data were collected through in-depth life histories with 21 subjects and suggest that gay and lesbian subjects perceive antihomosexual prejudice on the part of family members as one cause of childhood physical and sexual abuse.

Suspensory locomotion of Lagothrix lagothricha and Ateles belzebuth in Yasuní National Park, Ecuador.

A comparative field study of the locomotion of woolly monkeys (Lagothrix lagothricha) and spider monkeys (Ateles belzebuth) in undisturbed rainforest of northeastern Ecuador reveals substantial differences in their use of suspensory modes. Ateles performed both more brachiation (by forelimbs and tail, with trunk rotation), and forelimb swing (similar to brachiation, but without trunk rotation) than Lagothrix. In contrast, in Lagothrix 20% of suspensory movement was by pronograde forelimb swing, which resembles forelimb swing except that the body is held in a pronograde orientation due to the tail and/or feet intermittently grasping behind the trailing forelimb. Ateles never exhibited this mode. Both brachiation and forelimb swing by Ateles were more dynamic than in Lagothrix, consisting of higher proportions of full-stride bouts (versus single-step). Both species used smaller supports for suspensory than for quadrupedal locomotion, and Ateles used both smaller and larger supports for suspension than did Lagothrix. Analysis of support inclination shows that both species tended to perform more above-support movement on horizontal supports and more below-support (suspensory) movement from oblique supports. Our attempt to elucidate the aspects of canopy structure that favor suspension suggests the need for additional kinds of observational data, focusing on the "immediate structural context" of positional events.

Quantitative polymerase chain (QPCR) reaction using the MIMIC approach to estimate Cryptosporidium parvum oocysts, an intestinal pathogen, in municipal water treatment sludge samples.

An accurate estimation of the number of Cryptosporidium parvum oocysts in water treatment plant sludge was determined using the Quantitative Polymerase Chain Reaction (QPCR) method. Approximately 8x10(6)purified viable oocysts were spiked into raw water and treated by conventional water treatment methods. The settled sludge was collected and the DNA extracted. The QPCR Mimic produced two competing products that were 300 and 435 base pairs in size. The log ratio of the products were used in the standard curve to determine a final estimation of oocysts in the sludge sample. The final number of oocysts in the sludge sample was estimated at 258 oocyst per two litres of treated water. This is the first time sludge from a water treatment process has been tested for presence of C. parvum oocysts, which is a known contaminant of drinking water. The QPCR method can be used to test other sludge samples and help estimate the sanitary risks associated with using sludge to fertilize agricultural lands.

Identification and grouping of Dichelobacter nodosus, using PCR and sequence analysis.

Dichelobacter nodosus is the causative agent of ovine foot rot, a disease that is a constant economic burden for many Western sheep ranches. Vaccination is one method of treating foot rot. A higher and more specific immune response is observed when monovalent vaccines are used to treat foot rot, as compared to multivalent vaccines, which incorporate all 10 major New Zealand D. nodosus serogroups. There is no single assay for specifically identifying and grouping D. nodosus for the purpose of incorporating only the desired serogroup(s) in a vaccine. A polymerase chain reaction (PCR)-based assay was used to specifically identify and group D. nodosus from a foot rot lesion. Identification and grouping was determined by predicted fragment size analysis and nucleotide sequence information. The PCR approach vastly improves the accuracy in identifying and grouping D. nodosus from a foot rot lesion.

Characterization of the progesterone 21-hydroxylase activity of canine cytochrome P450 PBD-2/P450 2B11 through reconstitution, heterologous expression, and site-directed mutagenesis.

Canine hepatic cytochrome P450 PBD-2 metabolizes 2,2',4,4',5,5'-hexachlorobiphenyl and catalyzes the 21-hydroxylation of progesterone, thereby distinguishing PBD-2 as unique among 2B P450s. Heterologous expression of the PBD-2 cDNA, P450 2B11, in COS and yeast systems produced a protein capable of androstenedione metabolism; however, this P450 did not metabolize progesterone in a manner consistent with PBD-2. Modification of PBD-2 reconstitution parameters resulted in significantly increased catalytic activities and further emphasized differences between PBD-2 and the heterologously expressed enzyme. Subsequent Escherichia coli expression of 2B11 generated a protein that possessed substrate specificities indistinguishable from those of PBD-2 and provided a system in which the determinants of 2B11 progesterone 21-hydroxylation could be examined via site-directed mutagenesis. Site-directed mutants of 2B11 expressed in E. coli revealed that substitution of Ile with Val at position 363 converted 2B11 into a highly active and specific progesterone 16 alpha-hydroxylase. Mutants Val-114 --> Ile, Asp-290 --> Ile, and Ile-365 --> Phe exhibited decreased progesterone 21- and 16 alpha-hydroxylase activities, in accordance with decreases in androstenedione hydroxylase activities. In contrast, replacement of Ile-365 with Val or Leu resulted in much greater changes in progesterone than androstenedione hydroxylation. Thus, the combination of P450 reconstitution techniques, heterologous expression, and site-directed mutagenesis has revealed PBD-2 to be an important progesterone 21-hydroxylase in canine liver and has identified several amino acid residues that alter progesterone metabolism by 2B11.

Escherichia coli expression and characterization of cytochromes P450 2B11, 2B1, and 2B5.

Dog CYP2B11, rat CYP2B1, and rabbit CYP2B5 have been expressed in Escherichia coli from cDNAs modified at the N-terminus (Barnes et al., 1991, Proc. Natl. Acad. Sci. USA 88, 5597-5601). Using 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (Chaps), solubilized membranes representing > 100 nmol of P450 2B11, > 35 nmol of P450 2B1, and > 7 nmol of P450 2B5 were efficiently extracted (40-70% yield) from a 1-liter culture. Chaps-solubilized preparations produced a reduced CO/reduced difference spectrum devoid of P420 and were used directly in a reconstituted system. The E. coli-expressed 2B enzymes retained the same functional characteristics as the purified hepatic enzymes or enzymes expressed in COS cells in terms of androstenedione metabolite profiles. Hydroxylation rates were determined under a variety of conditions, including two concentrations of NADPH-cytochrome P450 reductase (2 and 16 nmol/nmol P450) and the absence or presence of cytochrome b5 (2 nmol/nmol P450). The androstenedione hydroxylase activities of expressed 2B1 and 2B5 were stimulated by cytochrome b5, whereas P450 2B11 was inhibited slightly by cytochrome b5. Purified expressed 2B11 (specific content, 8 nmol/mg protein) had similar activities as the Chaps-solubilized membrane preparation. The solubilized membranes containing 2B11 were also tested with 2,2',4,4',5,5'-hexachlorobiphenyl (245-HCB). Three major metabolites, 2-hydroxy-4,5,2',4',5'-pentachlorobiphenyl, 3-hydroxy-2,4,5,2',4',5'-hexachlorobiphenyl, and 2-hydroxy-3,4,5,2',4',5'-hexachlorobiphenyl were produced from 245-HCB. These metabolites are identical to those produced by 2B11 purified from liver microsomes. The 245-HCB hydroxylation rates were similar for E. coli-expressed 2B11, dog liver microsomes, and purified liver 2B11. When only the second codon in the 2B1 was changed to GCT, > 25 nmol of P450 was extracted from a 1-liter culture, suggesting that the full Barnes et al. modification scheme may not be necessary for high-level expression. An efficient method of expressing, extracting, and analyzing different P450 2B enzymes has thus been achieved. In addition, rabbit P450 2B5, which has never been purified from liver, as well as different P450 2B mutants can now be expressed at much higher levels than previously reported. The ability to express different 2B wild-type and mutant P450s in E. coli provides an excellent opportunity to study the molecular basis of species differences in substrate metabolism.

Site-directed mutagenesis of putative substrate recognition sites in cytochrome P450 2B11: importance of amino acid residues 114, 290, and 363 for substrate specificity.

Eleven amino acid residues unique to dog cytochrome P450 (P450) 2B11, compared with rat 2B1 and 2B2, rabbit 2B4 and 2B5, and mouse 2B10, in the putative substrate recognition sites [J. Biol. Chem. 267:83-90 (1992)] were mutated to the residues found in 2B1 or 2B5. The mutants were expressed initially in COS cells and screened for activity toward androstenedione and 2,2',4,4',5,5'-hexachlorobiphenyl (245-HCB). P450 2B11 mutants V107I, M199L-N200E-V204R, V234I, A292L, Q473R, and I475S showed no differences from wild-type P450 2B11 in metabolite profiles with either substrate. Mutants V114I, D290I, and L363V exhibited altered androstenedione metabolite profiles and were expressed in Escherichia coli for further study with androstenedione, testosterone, 7-ethoxycoumarin, (R)- and (S)-warfarin, and 245-HCB. With V114I, hydroxylation of steroids and warfarin and 2-hydroxylation of 245-HCB were decreased, whereas 7-ethoxycoumarin O-dealkylation and 3-hydroxylation of 245-HCB were unaltered. For D290I, activities toward all substrates were decreased, except for 16 beta-hydroxylation of testosterone. The activity of L363V was increased 5-6-fold for 16 alpha-hydroxylation of androstenedione and testosterone but was decreased to 40-50% of wild-type activity with 7-ethoxycoumarin and warfarin and to 6-8% of control for 2-hydroxylation of 245-HCB. Alignment of P450 2B11 with P450 101 and super-imposition of the 11 mutated 2B11 residues on a P450 101 three-dimensional model suggest that only residues 114, 290, and 363 represent substrate contact residues, in excellent agreement with the experimental results. The data indicate the importance of the three residues 114, 290, and 363 in substrate specificity and regio- and stereoselectivity of P450 2B11 and also demonstrate that the effects of the mutations vary considerably with different substrates.

Polymerase chain reaction amplification of the constant and variable regions of the Bacteroides nodosus fimbrial gene.

Serogrouping of Bacteroides nodosus is based on antigenic differences in fimbriae of the different New Zealand prototype strains. Because of the time needed to isolate and grow pure cultures of B. nodosus and the difficulty in distinguishing between different serogroups because of cross-agglutination, a new DNA-based diagnostic approach based on the fimbrial gene sequence of B. nodosus was developed. Published nucleotide sequences of the fimbrial genes for serogroups A, G, D, and H showed conservation at the 5' end, coding for the N terminus, and variability at the 3' end, coding for the C terminus. The polymerase chain reaction was used to amplify both the constant and variable regions of the fimbrial genes. Constant-region oligonucleotide primers were used to amplify a 100-base-pair fragment from the constant regions of the fimbrial genes of 10 New Zealand serogroups. Serogroup-specific oligonucleotide primers for serogroups A and H allowed amplification of a 282-base-pair fragment from serogroup A and a 363-base-pair fragment from serogroup H. Thus, amplification of the constant and variable regions of the fimbrial gene allows rapid detection and grouping of B. nodosus.

Age assessment using cementum annulus counts and tooth wear in a free-ranging population of Macaca mulatta.

Estimates were made of the tooth wear and the number of cementum annuli on lower first molars of Macaca mulatta of known age that had lived on Cayo Santiago, Puerto Rico. It is demonstrated that both these measurements are significantly correlated with age. Neither measurement by itself, however, strongly enough corrected with age to provide a reliable guide to the true age of individuals older than about 14 years, although cementum annulus counts clearly provide a more reliable guide to age determination than does wear. A combination of tooth wear and annulus number is a somewhat better predictor of age, with a multiple regression explaining 19% of the overall variance in age. As has been reported previously in tropical ungulates, there is more than one cementum annulus per year deposited on the M1S of our sample. Comparison with rainfall data indicates that the number of dry intervals in the animal's life corresponds on a one-to-one basis with the number of annuli. It is hypothesized that such dry intervals cause nutritional stress, which in turn is reflected in periods of arrested or slowed growth in the tooth cementum. Also, more annuli are formed per year on the teeth of males than those of females. Stress engendered by intermale competition may play a role in this phenomenon.

Positional behavior of female bornean orangutans (Pongo pygmaeus).

Observational data were collected on the positional behavior of habituated adult female orangutans in the rain forest of the Kutai National Park, East Kalimantan, Indonesia. Results revealed the following about locomotion during travel: movement was concentrated in the understory and lower main canopy; and brachiation (without grasping by the feet) accounted for 11% of travel distance, quadrupedalism for 12%, vertical climbing for 18%, tree-swaying for 7%, and clambering for 51%. In climbing and clambering, the animal was orthograde and employed forelimb suspension with a mixture of hindlimb suspension and support. Thus suspension by the forelimbs occurred in at least 80% of travel. Locomotion in feeding trees resembled that during travel but with more climbing and less brachiation. Feeding was distributed more evenly among canopy levels than was travel, and use of postures (by time) included sitting 50%, suspension with the body vertical 11%, and suspension by hand and foot with the body horizontal 36%. The traditional explanation of the evolution of the distinctive hominoid postcranium stresses brachiation. More recently it has been proposed that climbing, broadly defined and partly equivalent to clambering in this study, is the most significant behavior selecting for morphology. The biomechanical similarity of brachiation and the orthograde clambering of orangutans precludes the present results from resolving the issue for the evolution of Pongo. The orangutan is by far the largest mammal that travels in forest canopy, and a consideration of the ways that its positional behavior solves problems posed by habitat structure, particularly the tapering of branches and gaps between trees, indicates that suspensory capacities have been essential in permitting the evolution and maintenance of its great body size.