Dogs in Schools: The Impact of Specific Human–Dog Interactions on Reading Ability in Children Aged 6 to 8 Years

Dog-assisted educational programs, including reading programs, are becoming an area of research focus, based on claims of various advantages for children. However, while available findings typically indicate benefits for the children involved, the low quality of evidence makes it difficult to draw valid inferences. In the current study three dog-assisted programs with clearly defined parameters were developed and evaluated. Sixty-three children, aged 6 to 8 years, were matched on age and gender and pseudo-randomly allocated to one of the three conditions. In one condition the children participated in eight 15–20 minute sessions over a four-week period, in which they worked in pairs to train a dog to complete obstacle course tasks. In a second condition the children spent the same amount of time reading out loud, in pairs, to a stationary dog. In the third condition children participated in normal classroom activities with a dog present in the classroom. This intervention ran for up to four hours per week over the four-week period. Validated measures were used to assess reading abilities pre- and post-intervention. From the results it appeared that children showed significant improvements across time for reading ability for all three conditions, including the condition with minimal dog contact, with no significant group or interaction effects. Exploratory analyses unexpectedly indicated that children who had lower starting abilities displayed the greatest levels of reading improvement. While it cannot be determined that these findings are the result of the presence of the dog alone, they nonetheless may indicate that dog-assisted reading programs are an effective means of benefitting those children who most need help to become fluent readers.     

Barriers To Biological Fieldwork: What Really Prevents Teaching Out of Doors?

This paper considers a range of factors that may contribute to an unwillingness or inability of teachers to participate in the teaching of biology through fieldwork. Through a synthesis of the views of both pre-service teachers in training and primary school teachers in practice we explore the relative importance of a wide range of potential barriers and potential responses to them in the context of the wider literature. We conclude that although fieldwork may be impeded by the interaction of a wide range of individual barriers, including an individual’s predisposition towards the outdoors, it is possible to group interacting barriers into two main areas: school culture and teacher confidence. It is also apparent that barriers may assume different levels of significance when considered in general terms rather than when applied to a particular context and that the significance of barriers may change through time. Encouragingly, we have also shown that in-service teachers have a willingness to overcome these barriers.     

Does Physical Contact with a Dog or Person Affect Performance of a Working Memory Task?

ABSTRACT

Working memory (WM) plays a critical role in the execution of a wide variety of cognitive tasks and predicts academic success. This study was designed to compare the impact of the presence of a dog or a person, and physical contact with them, on the performance of a WM task. It also exam- ined whether the impact differed for two dogs, and whether these factors im- pacted arousal during the WM task. College students (n=31, aged 18–23 years) performed a WM task in five counterbalanced conditions; dog-touch, dog-no-touch, person-touch, person-no-touch, and alone. Participants were randomly assigned to one of two dogs; Miniature Poodle (n=16) or Border Collie (n=15). The WM task involved replicating increasingly complicated se- quences of colored lights by touching them on an iPad^®. Linear mixed model analyses revealed there was a significant interaction between collaborator and touch (p=0.05); best WM scores occurred without touch with either the per- son or the dog present, and worst WM scores occurred when the participant was touching a dog. Analyzing WM test during the dog conditions, touch (p=0.027) and dog breed (p=0.042) contributed independently to it; task completion was worse when the poodle was present and better without touch. Physiological measures [heart rate (HR) and heart rate variability] during the ex- periment indicated that the WM task was physiologically arousing (p<0.001) compared with listening, and HR was higher when touching a person than a dog during the task (p<0.046). These results are consistent with facilitation of performance by the presence of an observer. If there is a beneficial effect on cognition from a dog, physical contact with the dog might not be a necessary component. Aspects of the dog (e.g., breed) are also likely factors in WM task performance. This study highlights the importance of situational characteristics in studies evaluating the impact of companion animals.     

What Are Lay Theories of Social Class?

Numerous studies have documented the effects of social class on psychological and behavioral variables. However, lay beliefs about how social class affects these dimensions have not been systematically tested. Studies 1 and 2 assessed lay beliefs about the association between social class and 8 variables (including psychological and behavioral tendencies and cognitive ability). Study 3 assessed lay beliefs about the Big five personality traits and social class, and study 4 reframed the 8 variables from study 1 in opposite terms and yielded similar results. Study 5 contained the variables framed as in both studies 1 and 4, and replicated those results suggesting that framing effects were not responsible for the effects observed. Interestingly, for the most part lay beliefs about social class did not differ as a function of participants’ own social class. In general people held relatively accurate and consistent stereotypes about the relationship between social class and well-being, health, intelligence, and neuroticism. In contrast lay beliefs regarding social class and reasoning styles, as well as relational, social, and emotional tendencies were less consistent and coherent. This work suggests that on the whole people’s beliefs about social class are not particularly accurate, and further that in some domains there are contradictory stereotypes about the consequences of social class.     

What Makes a Dog Adoptable? An Eye-Tracking Investigation

Humans readily attribute personality and behavioral traits to dogs, and these attributions influence decisions about adoption. This study focused on how these attributions could be influenced by breed and pose by using pictures of four breeds (Doberman Pinscher, Golden Retriever, pit bull, and Rottweiler) in 4 poses (dog sitting alone, sitting with a human, standing alone, and walking on a leash with a human). Participants rated each picture on friendliness, aggressiveness, and adoptability. Eye-tracking technology identified which specific features were represented in each picture to determine whether they had any effect on the judgments. Although the Golden Retriever was seen as most adoptable, pose differences had many significant effects that could be useful for increasing the adoptability of all breeds. Data also revealed facial areas that attracted more attention (e.g., faster time to first fixation and longer fixation duration), particularly when the dog was alone. Focus on these areas could help to optimize photographs to present dogs in the friendliest, least aggressive, and most adoptable way.     

A Critical Appraisal of Vitiligo Etiologic Theories. Is Melanocyte Loss a Melanocytorrhagy?

Common generalized vitiligo is an acquired depigmenting disorder characterized by a chronic and progressive loss of melanocytes from the epidermis and follicular reservoir. However, the mechanism of melanocyte disappearance has never been clearly understood, and the intervention of cellular and humoral autoimmune phenomena as primary events remains unproven. In this review, is discussed the data supporting the major theories of vitiligo, namely melanocyte destruction (autoimmune, neural and impaired redox status) and melanocyte inhibition or defective adhesion. Based on recent morphologic findings in vivo supporting a chronic detachment and transepidermal loss of melanocytes in common generalized vitiligo, a new theory is suggested proposing melanocytorrhagy as the primary defect underlying melanocyte loss, integrating most of the possible triggering/precipitating/enhancing effects of other known factors.     

One Dog,but Which Dog? How Researchers Guide Participants to Select Dogs in Surveys of Human–Dog Relationships

Surveys and questionnaires are regularly used in studies of human–animal relationships. However, little attention has been given to understanding how survey participants are provided with instructions for the selection of a single animal within a multi-pet household, let alone the implications for reporting and interpreting data. We reviewed the instructions for the selection of an individual animal in studies addressing emotional or psychological attachment between people and dogs. By searching multidisciplinary journals from the year 2000 onwards, we identified a total of 128 papers, of which 63 met the inclusion criteria. Where selection criteria/instructions were not clear, authors were contacted. One in five studies (21%, or n = 13) did not report their instructions. When provided, instructions varied considerably. The most commonly provided direction was “favorite/closest relationship” (n = 12, or 19%). The remainder (n = 38, or 60%) were spread across eight different categories. Around half of the studies used a validated questionnaire that already contained an instruction, though a similar proportion of studies implemented author-designed instruments. Overall, the common absence and inconsistency of instructions for individual dog selection is taken to imply that there is no standard expectation or approach for instructions to be reported in studies of human relationships with dogs, or human–animal relationships more generally. We recommend further research on the implication of selection methods to ensure that instructions can be matched with specific research aims.     

Is That Dog a Pit Bull? A Cross-Country Comparison of Perceptions of Shelter Workers Regarding Breed Identification

Bull breeds are commonly kept as companion animals, but the pit bull terrier is restricted by breed-specific legislation (BSL) in parts of the United States and throughout the United Kingdom. Shelter workers must decide which breed(s) a dog is. This decision may influence the dog's fate, particularly in places with BSL. In this study, shelter workers in the United States and United Kingdom were shown pictures of 20 dogs and were asked what breed each dog was, how they determined each dog's breed, whether each dog was a pit bull, and what they expected the fate of each dog to be. There was much variation in responses both between and within the United States and United Kingdom. UK participants frequently labeled dogs commonly considered by U.S. participants to be pit bulls as Staffordshire bull terriers. UK participants were more likely to say their shelters would euthanize dogs deemed to be pit bulls. Most participants noted using dogs' physical features to determine breed, and 41% affected by BSL indicated they would knowingly mislabel a dog of a restricted breed, presumably to increase the dog's adoption chances.     

Split Personality of a Potyvirus: To Specialize or Not to Specialize?

Bean yellow mosaic virus (BYMV), genus Potyvirus, has an extensive natural host range encompassing both dicots and monocots. Its phylogenetic groups were considered to consist of an ancestral generalist group and six specialist groups derived from this generalist group during plant domestication. Recombination was suggested to be playing a role in BYMV''s evolution towards host specialization. However, in subsequent phylogenetic analysis of whole genomes, group names based on the original hosts of isolates within each of them were no longer supported. Also, nine groups were found and designated I-IX. Recombination analysis was conducted on the complete coding regions of 33 BYMV genomes and two genomes of the related Clover yellow vein virus (CYVV). This analysis found evidence for 12 firm recombination events within BYMV phylogenetic groups I–VI, but none within groups VII–IX or CYVV. The greatest numbers of recombination events within a sequence (two or three each) occurred in four groups, three which formerly constituted the single ancestral generalist group (I, II and IV), and group VI. The individual sequences in groups III and V had one event each. These findings with whole genomes are consistent with recombination being associated with expanding host ranges, and call into question the proposed role of recombination in the evolution of BYMV, where it was previously suggested to play a role in host specialization. Instead, they (i) indicate that recombination explains the very broad natural host ranges of the three BYMV groups which infect both monocots and dicots (I, II, IV), and (ii) suggest that the three groups with narrow natural host ranges (III, V, VI) which also showed recombination now have the potential to reduce host specificity and broaden their natural host ranges.     

Are Sick Individuals Weak Competitors? Competitive Ability of Snails Parasitized by a Gigantism-Inducing Trematode

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.     

Review on Dog Rabies Vaccination Coverage in Africa: A Question of Dog Accessibility or Cost Recovery?

Background

Rabies still poses a significant human health problem throughout most of Africa, where the majority of the human cases results from dog bites. Mass dog vaccination is considered to be the most effective method to prevent rabies in humans. Our objective was to systematically review research articles on dog rabies parenteral vaccination coverage in Africa in relation to dog accessibility and vaccination cost recovery arrangement (i.e.free of charge or owner charged).

Methodology/Principal Findings

A systematic literature search was made in the databases of CAB abstracts (EBSCOhost and OvidSP), Scopus, Web of Science, PubMed, Medline (EBSCOhost and OvidSP) and AJOL (African Journal Online) for peer reviewed articles on 1) rabies control, 2) dog rabies vaccination coverage and 3) dog demography in Africa. Identified articles were subsequently screened and selected using predefined selection criteria like year of publication (viz. ≥ 1990), type of study (cross sectional), objective(s) of the study (i.e. vaccination coverage rates, dog demographics and financial arrangements of vaccination costs), language of publication (English) and geographical focus (Africa). The selection process resulted in sixteen peer reviewed articles which were used to review dog demography and dog ownership status, and dog rabies vaccination coverage throughout Africa. The main review findings indicate that 1) the majority (up to 98.1%) of dogs in African countries are owned (and as such accessible), 2) puppies younger than 3 months of age constitute a considerable proportion (up to 30%) of the dog population and 3) male dogs are dominating in numbers (up to 3.6 times the female dog population). Dog rabies parenteral vaccination coverage was compared between “free of charge” and “owner charged” vaccination schemes by the technique of Meta-analysis. Results indicate that the rabies vaccination coverage following a free of charge vaccination scheme (68%) is closer to the World Health Organization recommended coverage rate (70%) than the achieved coverage rate in owner-charged dog rabies vaccination schemes (18%).

Conclusions/Significance

Most dogs in Africa are owned and accessible for parenteral vaccination against rabies if the campaign is performed “free of charge”.     

Do They Ever Come Back? Responses of Leafhopper Communities to Extensification of Land Use

We studied leafhopper communities in meadows subject to progressive extensification of land use, particularly (i) delay of the first cut, (ii) cessation of fertilising and (iii) reduction of cutting events. Within a gradient from conventionally used high-productivity meadows (as control) through our extensified plots to extensively managed wet hay meadows (as control), we found an increasing species number correlated with extensification of land use. However, a separate analysis of generalists and specialists showed that the latter group increased significantly whereas generalists did not respond at all. Even after 12 years of extensification there was only little evidence for the recovery or recolonisation of former hay meadow insect communities. Instead the increase in species numbers was rather due to immigration of more xerophilous or mesophilous species. We conclude that leafhoppers principally respond positively to extensification of land use, but that restoration of former moisture conditions is necessary in order to achieve a full recovery of original hay meadow communities. Finally we propose a model extensification ecogram for meadow leafhoppers which can be used as a predictive tool for extensification and as an indicator of restoration progress and success.     

Isolation of a Bacterial Strain with the Ability To Utilize the Sulfonated Azo Compound 4-Carboxy-4′-Sulfoazobenzene as the Sole Source of Carbon and Energy

A bacterial strain (strain S5) which grows aerobically with the sulfonated azo compound 4-carboxy-4′-sulfoazobenzene as the sole source of carbon and energy was isolated. This strain was obtained by continuous adaptation of “Hydrogenophaga palleronii” S1, which has the ability to grow aerobically with 4-aminobenzenesulfonate. Strain S5 probably cleaves 4-carboxy-4′-sulfoazobenzene reductively under aerobic conditions to 4-aminobenzoate and 4-aminobenzene-sulfonate, which are mineralized by previously established degradation pathways.It is generally assumed that sulfonated azo dyes are not degraded under aerobic conditions (14). Nevertheless, there have been some reports which suggest a conversion of certain sulfonated azo dyes under aerobic conditions (3, 7, 8, 13, 15). Furthermore, certain carboxylated analogs of sulfonated azo compounds are utilized aerobically as the sole source of carbon and energy by specifically adapted bacteria (11, 12, 16, 17). However, unequivocal evidence for the productive mineralization of a sulfonated azo compound by bacteria is lacking. In the present article the first observation of the utilization of a sulfonated azo compound as the sole source of carbon and energy by a bacterial strain is reported.Previously, a mixed bacterial culture which mineralizes sulfanilate (4-aminobenzenesulfonate) was isolated. This coculture consisted of the strains “Hydrogenophaga palleronii” S1 and Agrobacterium radiobacter S2 (4, 5). Because sulfanilate occurs as an azoaryl structural element in many azo dyes, it was of interest whether this mixed culture could adopt the ability to reduce azo bonds and release sulfanilate as growth substrate. Therefore, the model sulfonated azo compound 4-carboxy-4′-sulfoazobenzene (CSAB) was synthesized by nitro-amine condensation starting with sulfanilic acid and 4-nitrobenzoic acid (1). The precipitated CSAB was separated from the reaction mixture by filtration and purified by repeated dissolution in alkali and precipitation with acid. The identity and purity of the bright orange product were analyzed by UV-visible light spectroscopy, elementary analysis, and high-pressure liquid chromatography (HPLC). For the solid material obtained, molar extinction coefficients of 23.74 and 1.13 mM⁻¹ cm⁻¹ in water were determined at the wavelengths of 326 and 434 nm, respectively. The elementary analytic results were consistent with the structure of CSAB. The purity of the preparation was tested by HPLC with a reversed-phase column and a solvent gradient from 1 to 90% (vol/vol) methanol and 0.3% (vol/vol) H₃PO₄. A single band which showed absorbance at a wavelength of 326 nm was eluted. At 210 nm a minor contaminant (about 15% of the signal intensity of CSAB) was detected. This compound was clearly different from either 4-nitrobenzoate or sulfanilate.The mixed culture was grown in repeated batch cultures in a mineral medium with sulfanilate (5 mM). About every 2 weeks the culture was transferred (1:10 [vol/vol]) to fresh medium, in which the sulfanilate concentration was subsequently reduced and the CSAB concentration increased (±0.5 mM each). The color of the azo dye disappeared after 2 months. The culture was transferred to a solid mineral medium with CSAB as the sole source of carbon. From this culture was obtained strain S5, which grew aerobically with the sulfonated azo compound CSAB as its sole source of carbon and energy and with a doubling time of 9.5 h (Fig. ​(Fig.1).1). The complete disappearance of the dye was demonstrated by the loss of the orange color from the medium and by HPLC analysis, whereas CSAB was not degraded in a sterile control flask. Based on its colony morphology and the results obtained with the commercial identification system Biolog GN, this strain strongly resembled “H. palleronii” S1. Recently, it was demonstrated that, in the presence of low concentrations of biotin, cyanocobalamin, and 4-aminobenzoate, strain S1 also grows in axenic culture with sulfanilate (2). Therefore the adaptation experiment was repeated in the presence of these three substances with a pure culture of strain S1. This experiment also resulted in the isolation of a strain which grew in axenic culture with CSAB as the sole source of carbon and energy. Open in a separate windowFIG. 1Aerobic growth of strain S5 with CSAB as the sole source of carbon and energy. The growth was determined photometrically (OD₅₄₆), and the turnover of CSAB was measured by HPLC with a reversed-phase column and a solvent gradient consisting of H₂O, methanol, and 0.3% H₃PO₄ with increasing concentrations of methanol (1 to 90%). An OD₅₄₆ of 1 corresponded to 0.33 mg of protein ml⁻¹.To ensure that the genetic backgrounds of strains S5 and S1 were identical, the genes for the 16S rRNAs were amplified by PCR with different universal primers (6) and sequenced in comparison to the corresponding gene from the type strain, H. palleronii DSM 63. It was found that the sequences from strains S1 and S5 were > 99.8% identical (there were only two discrepancies between the two sequences), but they showed only 97.7 to 97.9% identity with the 16S rRNA gene from H. palleronii DSM 63. It was therefore concluded that strain S5 was derived from strain S1 and that the strains do not belong to the species H. palleronii.A reductive cleavage of the azo bond of CSAB would result in the formation of 4-aminobenzoate and sulfanilate. Like the parent strain, S1, strain S5 grew in the presence of sulfanilate, 4-aminobenzoate, and 4-sulfocatechol. The doubling times with these compounds were 6.2 to 6.4 h. We therefore investigated whether reductive cleavage of CSAB by strain S5 occurs. Strain S5 was grown aerobically with 5 mM CSAB, and cell extracts were prepared (10) in different buffers. These cell extracts were incubated aerobically in cuvettes containing 50 mM Tris-HCl buffer (pH 8.0), 0.5 mM CSAB, 1 mM NADH, or 1 mM NADPH and with various mixtures of possible cofactors. The enzyme activity was measured spectrophotometrically at the absorption maximum for CSAB (at a wavelength of 434 nm), but no significant decrease in absorbance was observed. Neither addition of a membrane fraction nor performing the enzyme assays under anaerobic conditions (9) improved the turnover of CSAB in the cell-free system. Furthermore, there was no significant increase in azo reductase activity when harvested cells were resuspended in the culture supernatant instead of Tris-HCl buffer.The maximal enzyme activities observed for cell extracts were only about 30% of the activities found for intact cells. This suggested that during the disruption of the cells some important components of the azo reductase system were destroyed or some cofactors were present in only limiting quantities.Because it was difficult to obtain reproducible enzyme activities with cell extracts, the turnover of CSAB by resting cells was investigated. Cells of strain S5 were grown with CSAB (5 mM), harvested by centrifugation, resuspended in Tris-HCl at an optical density at 546 nm (OD₅₄₆) of 5.3, and incubated in a water bath shaker (140 rpm; 30°C) with 0.5 mM CSAB (Fig. ​(Fig.2).2). Thus, the transient accumulation of two metabolites in the supernatants was observed by reversed-phase HPLC (column size, 250 by 4.6 mm) (SIL 100; Grom, Herrenberg, Germany). The solvent system consisted of a solvent gradient with increasing concentrations of methanol, starting with 1% (vol/vol) methanol, 98.9% (vol/vol) water, and 0.1% H₃PO₄. The flow rate was 0.7 ml min⁻¹. The metabolites formed were identified as sulfanilate and 4-sulfocatechol by comparison of their retention times and in situ UV-visible light-spectra with authentic standards. Surprisingly, the concentration of 4-sulfocatechol in the medium increased (and decreased) during the experiment more rapidly than the concentration of sulfanilate (Fig. ​(Fig.2).2). 4-Sulfocatechol also temporarily accumulated when resting cells of strain S1 were incubated with sulfanilate (4, 5). This suggested that in the resting-cell assay the initial activity of the sulfanilate-converting enzyme was higher than the activity of the 4-sulfocatechol-oxidizing enzyme protocatechuate-3,4-dioxygenase type II. Presumably, the activity of the sulfanilate-converting enzyme decreased during the experiment more rapidly than the activity of protocatechuate-3,4-dioxygenase type II. No accumulation of 4-aminobenzoate or protocatechuate was found by HPLC analysis during the experiment. In a control experiment with cells of strain S1 grown with 4-aminobenzenesulfonate, no turnover of CSAB was observed by HPLC analysis. Open in a separate windowFIG. 2Conversion of CSAB (•) to sulfanilate (▪) and 4-sulfocatechol (□) by resting cells of strain S5. Strain S5 was grown in a mineral medium with CSAB as the sole source of carbon and energy, and resting cells were prepared as described in the text.The detection of sulfanilate derived from CSAB suggested a reductive cleavage of CSAB, yielding sulfanilate as one of the reduction products. This reaction should also proceed in the absence of oxygen. Therefore, resting cells were incubated under anaerobic conditions with CSAB. Surprisingly, the rate of CSAB turnover under anaerobic conditions was <2% of the turnover rate under aerobic conditions.A further indication of a reductive cleavage of CSAB into sulfanilate and 4-aminobenzoate was obtained by growing strain S5 with CSAB or a complex medium (HPG medium) (4). When the cells were grown in a mineral medium with CSAB and the turnover of the substrates was analyzed by HPLC, it was found that resting cells converted CSAB, 4-aminobenzoate, or 4-aminobenzenesulfonate with specific activities of 0.012, 0.026, and 0.011 μmol min⁻¹ mg of protein⁻¹, respectively. In contrast, after growth of the cells in HPG medium, these activities were only 0.007, 0.010, and 0.003 μmol min⁻¹ mg of protein⁻¹, respectively. Incubation of resting cells with CSAB and different potential inhibitors of ring cleavage dioxygenases showed that the turnover of CSAB was almost completely inhibited by the addition of 8-hydroxyquinoline or 2,2′-bipyridyl (1 mM each). The presence of 4-nitrocatechol (0.25 mM) also resulted in a pronounced reduction of the rate of CSAB turnover (6% of the rate in the absence of the inhibitor). In this system as well the formation of 4-sulfocatechol was observed.The degradation of sulfanilate and 4-aminobenzoate by strain S1 has been previously studied (5). The proposed degradation pathway for CSAB and its reduction products is shown in Fig. ​Fig.3.3. Open in a separate windowFIG. 3Proposed pathway for the degradation of CSAB by strain S5. 4AB, 4-aminobenzoate; 4ABS, 4-aminobenzenesulfonate (sulfanilate); 3,4DHB, 3,4-dihydroxybenzoate (protocatechuate); 4SC, 4-sulfocatechol; 2H4CMSA, 2-hydroxy-4-carboxymuconic semialdehyde; 3SM, 3-sulfomuconate; 4SL, 4-carboxymethyl-4-sulfobut-2-en-4-olide (4-sulfolactone); MA, maleylacetate; 3OA, 3-oxoadipate; TCC, tricarboxylic acid cycle.To obtain some information about the substrate specificity, resting cells were incubated with CSAB, 4,4′-dicarboxyazobenzene (DCAB), 4-hydroxy-4′-sulfoazobenzene, methyl orange [4-(N,N-dimethyl)-4′-sulfoazobenzene; color index (C.I.) 13025], orange II {4-[(2-hydroxy-1-naphthalenyl)azo]-benzenesulfonic acid; C.I. 15510}, or sunset yellow FCF {6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthol-6-sulfonic acid; FD&C no. 6; C.I. 15985}. Of these compounds, only CSAB and DCAB were converted by resting cells. DCAB was also utilized by strain S5 as the sole source of carbon and energy. Furthermore, no growth of strain S5 was found with acid black 24 and 52, acid blue 113, acid red 1, amaranth, direct red 81, direct yellow 4 and 50, mordant yellow 3, and naphthol blue black.The results presented in this study suggest that bacterial cultures with the ability to aerobically degrade simple sulfonated azo dyes may be obtained after preadaptation to sulfonated aminoaromatics and/or when reductive cleavage of the azo bond gives rise to an aerobically assimilable aminoaromatic structure, like 4-aminobenzoate. This selection scheme circumvents the problems observed during attempts to adapt bacteria with the ability to degrade carboxylated azo compounds for the degradation of sulfonated azo compounds (12). The ability of strain S5 to mineralize CSAB suggests that it is possible to degrade sulfonated azo dyes under aerobic conditions if biological systems which can grow and can mineralize the reduction products are available.

Nucleotide sequence accession number.

The nucleotide sequences for the 16S rRNAs from strains S5 and S1 have been deposited in the GenBank data library under accession no. {"type":"entrez-nucleotide","attrs":{"text":"AF019037","term_id":"3004497","term_text":"AF019037"}}AF019037 and {"type":"entrez-nucleotide","attrs":{"text":"AF019073","term_id":"3004495","term_text":"AF019073"}}AF019073, respectively.     

Work Ability of Health Care Shift Workers: What Matters?

This paper aims at identifying variables associated with inadequate work ability among nursing personnel at a public hospital, considering factors related to socio‐demographic, lifestyles, working conditions, and health outcomes. A cross‐sectional study was conducted in a university hospital in São Paulo, Brazil, as part of a larger research study on tolerance to 12 h night work. Nursing staff included registered nurses, nurse technicians, and nurse aides; in total, there were 996 healthcare workers (878 female; 118 male) at the time of the study. Some 696 workers (69.9%) of the population agreed to participate. Data collection (October 2004–July 2005) was based on a comprehensive questionnaire about living and working conditions (including incivility at work, work demands, work control, and support), mental and physical health symptoms (fatigue and sleep problems), and work ability. This report presents analyses of the adapted Brazilian version of the Work Ability Index (WAI) and associated variables. The study population worked one of the following shift schedules at this hospital: 12 h nights followed by 36 h off or 9 h or 6 h day (morning or afternoon) shifts. The mean age of the respondents was 34.9 (S.D.±10.4) years of age; 31.5% of the participants held two jobs. Statistical analyses using a hierarchical multiple logistic regression model were performed to evaluate the factors associated with inadequate (moderate and low scores) of the WAI. The significantly associated factors were socio‐demographic (income responsibility, sole breadwinner, raising kids, age group), working conditions (thermal discomfort, organization of the workplace, and verbal abuse), and health outcomes (high body mass index, obesity, sleep problems, and fatigue). In spite of limitations of the study design, results indicate that the nursing profession is associated with stressful working conditions, contributing to inadequate WAI. This is in addition to bad living conditions and precarious work. Intervention measures, either at the workplace or at individual levels, are necessary to prevent a decrease in work ability, even in this quite young working population.