Diatom Assemblages and their Associations with Environmental Variables in Oregon Coast Range Streams, USA

The Oregon Coast Range, rich in natural resources, is under increasing pressure from rapid development. The purpose of this study was to examine diatom species patterns in relation to environmental variables in streams of this region. Diatoms, water quality, physical habitat and watershed characteristics were assessed for 33 randomly selected stream sites. Watershed size, elevation, geology, vegetation and stream morphology varied substantially among sites. Streams were characterized by dilute water chemistry and a low percent of fine substrate. A total of 80 diatom taxa were identified. Taxa richness was low throughout the region (median 15, range 10–26). Assemblages were dominated by two adnate species, Achnanthidium minutissimum and Achnanthes pyrenaicum. Diatoms sensitive to organic pollution dominated the assemblages at all sites (median 85%). Non-metric multidimensional scaling (NMDS) and correlational analysis showed quantitative relationships between diatom assemblages and environmental variables. NMDS axes were significantly correlated with watershed area, watershed geology, conductivity, total nitrogen, total solids and stream width. Diatom-based site classification (Two-way Indicators Species Analysis, (TWINSPAN)) yielded 4 discrete groups that displayed weak correlations with environmental variables. When stream sites were classified by dominant watershed geology, overall diatom assemblages between groups were significantly different (Analysis of Similarity (ANOSIM) global R = 0.19, p < 0.05). Our results suggest that streams in the coastal region are in relatively good condition. High natural variability in stream conditions in the Oregon Coast Range ecoregion may obscure quantitative relationships between environmental variables and diatom assemblages. A bioassessment protocol that classifies sites by major landscape variables and selects streams along the major human disturbance gradient might allow for detection of early signs of human disturbance in environmentally heterogeneous regions, such as the Pacific Northwest.     

Personality Effects on Romantic Relationship Quality through Friendship Quality: A Ten-Year Longitudinal Study in Youths

This study examined whether individuals with different personality types (i.e., overcontrollers, undercontrollers, resilients) had different friendship quality development throughout adolescence. It also investigated whether personality types were indirectly related to romantic relationship quality in young adulthood, via friendship quality development in adolescence. The study employed six waves of longitudinal questionnaire data from Dutch youths who had a romantic relationship when they were young adults. Two age cohorts were followed, from 12 to 21 years and from 16 to 25 years, respectively. Findings showed that resilients reported higher mean levels of friendship quality during adolescence (i.e., more support from, less negative interaction with and less dominance from their best friend) than both overcontrollers and undercontrollers. Through the mean levels of friendship quality throughout adolescence, resilients indirectly experienced higher romantic relationship quality during young adulthood than both overcontrollers and undercontrollers. Thus, results provide support for a developmental model in which adolescent friendship quality is a mechanism linking personality types with young adulthood romantic relationship quality.     

Assessment of Enteric Pathogen Shedding by Bathers during Recreational Activity and its Impact on Water Quality

An assessment was made to determine the potential loading of enteric pathogenic protozoa and viruses into drinking water supply reservoirs by body contact recreation. These and other organisms of fecal origin are shed from the body during bathing. A literature review was conducted on the concentration of selected enteric viruses and protozoa during infection, the incidence of these infections, and duration of excretion. In addition, from existing literature, the amount of fecal material released during bathing was estimated from the shedding of fecal coliforms by bathers. The mean amount of fecal material shed per bather was estimated at 0.14[emsp4 ]gram. The concentration of protozoan parasites (Giardia or Cryptosporidium) in feces of infected persons can range from 10⁵ to 10⁷ per gram and enteric viruses (enteroviruses, adenoviruses, rotavirus) from 10⁵ to 10¹² per gram. From this information, the concentration of enteric pathogens, shed into the water, could be calculated for a group of bathers. This information can be used to model the impact of body contact recreation on water quality in reservoirs used for drinking water supplies. Such information is useful in assessing the required treatment of the water to meet water quality regulations.     

A Rapid,Specific Membrane Filtration Procedure for Enumeration of Enterococci in Recreational Water

A two-step membrane filter (MF) method with mE medium, upon which the membrane must be incubated for 48 h and then transferred to a substrate medium to differentiate enterococci, is recommended by the U.S. Environmental Protection Agency to measure enterococci in fresh and marine recreational waters. The original mE medium was modified by reducing the triphenyltetrazolium chloride from 0.15 to 0.02 g/liter and adding 0.75 g of indoxyl β-d-glucoside per liter. The new MF medium, mEI medium, detected levels of enterococci in 24 h comparable to those detected by the original mE medium in 48 h, with the same level of statistical confidence. In addition, the use of mEI medium eliminated the need to transfer the membrane to a substrate medium to differentiate enterococci from other genera of the fecal streptococcal group. Colonies from mEI medium were examined to determine the rates of false-positive and false-negative occurrences. mEI medium had a false-positive rate of 6.0% and a false-negative rate of 6.5%. Interlaboratory testing of the MF method with mEI medium demonstrated that the relative reproducibility standard deviations among laboratories ranged from 2.2% for marine water to 18.9% for freshwater. The comparative recovery studies, specificity determinations, and multilaboratory evaluation indicated that mEI medium has analytical performance characteristics equivalent to those of mE medium. The simplicity of use and decreased incubation time with mEI medium will facilitate the detection and quantification of enterococci in fresh and marine recreational waters.The use of enterococci as an indicator of fecal contamination of recreational water was recommended by the U.S. Environmental Protection Agency (13) in 1986. The recommendation was based on studies which demonstrated that enterococci had a strong direct relationship to swimming-associated illness in both marine water (3) and freshwater (7) environments. A two-step membrane filter (MF) procedure described by Levin et al. (11) was used to quantify enterococci in these studies and is the procedure recommended for measuring the quality of recreational water by the U.S. Environmental Protection Agency Ambient Water Quality Criteria for Bacteria—1986 (13).The two-step MF procedure for enterococci requires 48 h of incubation of the MF at 41°C on a selective primary isolation medium (mE agar) followed by transfer of the MF to an in situ esculin-iron agar (EIA) substrate medium, which is incubated for 20 min at 41°C. Pink to red colonies on the MF that produce a brownish black precipitate on EIA are identified as enterococci. The brownish black precipitate formed on EIA is the result of the hydrolysis of esculin to glucose and coumarin by the enzyme β-glucosidase. Coumarin forms a black precipitate in the presence of ferric citrate. The selective characteristics of the primary isolation medium (mE agar) result from the addition of nalidixic acid, cycloheximide (Acti-Dione), and triphenyltetrazolium chloride (TTC) to the medium and the elevated incubation temperature of 41°C. Nalidixic acid inhibits gram-negative bacteria, cycloheximide inhibits fungi, and TTC (0.15 g/liter) differentiates enterococci from other gram-positive cocci and inhibits background organisms. The specificity of the medium was reported to be 10% false-positive and 11.7% false-negative (11).In 1980, Dufour (6) described a medium, similar to that of Levin et al. (11), for use in a single-step, 24-h MF procedure to enumerate enterococci in marine water and freshwater. The medium contained nalidixic acid, cycloheximide, a reduced concentration of TTC, and indoxyl β-d-glucoside, a chromogenic cellobiose analog used in place of esculin in the primary medium of Levin et al. (11) to differentiate enterococci from fecal streptococci. The addition of indoxyl β-d-glucoside into microbiological media results in β-glucosidase-positive enterococci producing an insoluble indigo blue complex which diffuses into the surrounding media, forming a blue halo around the colony.The present study was undertaken to (i) evaluate modifications to the commercially available base medium mE agar which would produce recovery of enterococci equivalent to that in the two-step, 48-h procedure in a single-step, 24-h procedure; (ii) determine the specificity of the modified medium (mEI medium) for enterococci; and (iii) determine, through collaborative study, the variability among laboratories using mEI medium for samples from various aquatic environments.     

Multiple Stressors in Agricultural Streams: A Mesocosm Study of Interactions among Raised Water Temperature,Sediment Addition and Nutrient Enrichment

Changes to land use affect streams through nutrient enrichment, increased inputs of sediment and, where riparian vegetation has been removed, raised water temperature. We manipulated all three stressors in experimental streamside channels for 30 days and determined the individual and pair-wise combined effects on benthic invertebrate and algal communities and on leaf decay, a measure of ecosystem functioning. We added nutrients (phosphorus+nitrogen; high, intermediate, natural) and/or sediment (grain size 0.2 mm; high, intermediate, natural) to 18 channels supplied with water from a nearby stream. Temperature was increased by 1.4°C in half the channels, simulating the loss of upstream and adjacent riparian shade. Sediment affected 93% of all biological response variables (either as an individual effect or via an interaction with another stressor) generally in a negative manner, while nutrient enrichment affected 59% (mostly positive) and raised temperature 59% (mostly positive). More of the algal components of the community responded to stressors acting individually than did invertebrate components, whereas pair-wise stressor interactions were more common in the invertebrate community. Stressors interacted often and in a complex manner, with interactions between sediment and temperature most common. Thus, the negative impact of high sediment on taxon richness of both algae and invertebrates was stronger at raised temperature, further reducing biodiversity. In addition, the decay rate of leaf material (strength loss) accelerated with nutrient enrichment at ambient but not at raised temperature. A key implication of our findings for resource managers is that the removal of riparian shading from streams already subjected to high sediment inputs, or land-use changes that increase erosion or nutrient runoff in a landscape without riparian buffers, may have unexpected effects on stream health. We highlight the likely importance of intact or restored buffer strips, both in reducing sediment input and in maintaining cooler water temperatures.     

Effects of Multiple Use on Water Quality of High-Mountain Watersheds: Bacteriological Investigations of Mountain Streams

Bacteriological studies in 1968 and 1969 corroborated earlier findings that a municipal watershed which had been closed to public entry since 1917 yielded water with four to six times the coliform count found in an adjacent mountain watershed open to recreational activities. Similarly, chemical investigations showed higher concentrations of most ions in water from the closed area. Physiological differentiation of coliform and enterococcal bacteria revealed similar types of organisms in both animal droppings and stream water, with fecal coliforms accounting for as much as 70% of the coliform counts observed in the closed area in 1969. Opening of the closed drainage for limited recreation and expanded logging operations in the spring of 1970 coincided with an unexpected decrease in bacterial contamination of that stream. It is postulated that these human activities drove from the watershed a large wild animal population which had contributed substantially to the previous bacterial pollution. It would seem that the practice of closing high-mountain watersheds to public entry is questionable if governmental standards for water quality are to be met, and it also seems that the standards themselves should be reexamined.     

Colorimetric and Longitudinal Analysis of Leukocoria in Recreational Photographs of Children with Retinoblastoma

Retinoblastoma is the most common primary intraocular tumor in children. The first sign that is often reported by parents is the appearance of recurrent leukocoria (i.e., “white eye”) in recreational photographs. A quantitative definition or scale of leukocoria – as it appears during recreational photography – has not been established, and the amount of clinical information contained in a leukocoric image (collected by a parent) remains unknown. Moreover, the hypothesis that photographic leukocoria can be a sign of early stage retinoblastoma has not been tested for even a single patient. This study used commercially available software (Adobe Photoshop®) and standard color space conversion algorithms (operable in Microsoft Excel®) to quantify leukocoria in actual “baby pictures” of 9 children with retinoblastoma (that were collected by parents during recreational activities i.e., in nonclinical settings). One particular patient with bilateral retinoblastoma (“Patient Zero”) was photographed >7, 000 times by his parents (who are authors of this study) over three years: from birth, through diagnosis, treatment, and remission. This large set of photographs allowed us to determine the longitudinal and lateral frequency of leukocoria throughout the patient''s life. This study establishes: (i) that leukocoria can emerge at a low frequency in early-stage retinoblastoma and increase in frequency during disease progression, but decrease upon disease regression, (ii) that Hue, Saturation and Value (i.e., HSV color space) are suitable metrics for quantifying the intensity of retinoblastoma-linked leukocoria; (iii) that different sets of intraocular retinoblastoma tumors can produce distinct leukocoric reflections; and (iv) the Saturation-Value plane of HSV color space represents a convenient scale for quantifying and classifying pupillary reflections as they appear during recreational photography.     

Field Evaluation of a Semiautomated Method for Rapid and Simple Analysis of Recreational Water Microbiological Quality

An early warning system using a rapid enzymatic semiautomated method suitable for fecal coliform detection in recreational waters within 8 h was developed further and evaluated in this study. This rapid method was compared to the standard method followed in the United Kingdom. We used 1,011 samples originating from 206 different locations in Wales. When we assessed the presence or absence of fecal coliforms, targeting very low levels of contamination, we obtained 83.9% agreement between the rapid method and the lauryl sulfate broth-membrane filtration technique, whereas direct confirmation of the samples processed by the rapid method showed 89.3% agreement. Environmental enzymatic background activity was found to be the main limiting factor for this method. Owing to a specific and integrated handling of the results by the software of the instrument, the percentage of false-positive results (a consequence of enzymatic background) was successfully limited to 2.9% by the direct confirmation evaluation. However, 7.8% false-negative results due to “late-growers” had to be accepted in order to produce results within a working day. At present, the method can be used in a more conservative way to assess the environmental threshold of 100 CFU of fecal coliforms per 100 ml in recreational waters. The implications of our findings with regard to the applicability of rapid enzymatic methods are discussed.     

四种红树林植物的淡水驯化试验

选择秋茄、木榄、桐花树、无瓣海桑４ 种红树林植物的幼苗, 在中山大学附属中学校园内进行了８ 个月的池塘和陆地的淡水驯化试验。对之分别计算了成活率、茎高增加量、基茎增加量、生物量的增量和凋落物量, 并定期对其成活状况、生长状况进行观察和记录。发现各树种在淡水池塘中均能较好生长, 木榄和桐花树对陆地也有较强的适应性。     

国内外森林与水质研究综述

近几十年来,随着大面积的森林被不合理的采伐利用,使生态环境遭受巨大破坏。同时,近些年来,受全球气候异常的影响,水、旱灾频繁,水土流失严重,且由于环境污染,造成水质不断恶化,水质型缺水日益严重。为保护水资源,森林与水环境,森林与水质已成为近十年来森林水文学研究的重点和热点。国内外的一些专家、学者经过多年来的观测和研究,已取得很多成果。1　关于森林和水质的研究现状大约从本世纪50年代,我国开始关注森林对水质的影响[1]。不过国内绝大多数的研究是着重于森林对河流悬移泥沙含量的影响。直到七十八十年代,我国的一些科研院所,如…     

Race,Ideology, and the Tea Party: A Longitudinal Study

The Tea Party movement, which rose to prominence in the United States after the election of President Barack Obama, provides an ideal context in which to examine the roles of racial concerns and ideology in politics. A three-wave longitudinal study tracked changes in White Americans’ self-identification with the Tea Party, racial concerns (prejudice and racial identification), and ideologies (libertarianism and social conservatism) over nine months. Latent Growth Modeling (LGM) was used to evaluate potential causal relationships between Tea Party identification and these factors. Across time points, racial prejudice was indirectly associated with movement identification through Whites’ assertions of national decline. Although initial levels of White identity did not predict change in Tea Party identification, initial levels of Tea Party identification predicted increases in White identity over the study period. Across the three assessments, support for the Tea Party fell among libertarians, but rose among social conservatives. Results are discussed in terms of legitimation theories of prejudice, the “racializing” power of political judgments, and the ideological dynamics of the Tea Party.     

Longitudinal Study of Escherichia coli O157:H7 Dissemination on Four Dairy Farms in Wisconsin

A 14-month longitudinal study was conducted on four dairy farms (C, H, R, and X) in Wisconsin to ascertain the source(s) and dissemination of Escherichia coli O157:H7. A cohort of 15 heifer calves from each farm were sampled weekly by digital rectal retrieval from birth to a minimum of 7 months of age (range, 7 to 13 months). Over the 14 months of the study, the cohort heifers and other randomly selected cattle from farms C and H tested negative. Farm R had two separate periods of E. coli O157:H7 shedding lasting 4 months (November 1995 to February 1996) and 1 month (July to August 1996), while farm X had at least one positive cohort animal for a 5-month period (May to October 1996). Heifers shed O157:H7 strains in feces for 1 to 16 weeks at levels ranging from 2.0 × 10² to 8.7 × 10⁴ CFU per g. E. coli O157:H7 was also isolated from other noncohort cattle, feed, flies, a pigeon, and water associated with the cohort heifers on farms R and/or X. When present in animal drinking water, E. coli O157:H7 disseminated through the cohort cattle and other cattle that used the water source. E. coli O157:H7 was found in water at <1 to 23 CFU/ml. Genomic subtyping by pulsed-field gel electrophoresis demonstrated that a single O157:H7 strain comprised a majority of the isolates from cohort and noncohort cattle, water, and other positive samples (i.e., from feed, flies, and a pigeon, etc.) on a farm. The isolates from farm R displayed two predominant XbaI restriction endonuclease digestion profiles (REDP), REDP 3 and REDP 7, during the first and second periods of shedding, respectively. Six additional REDP that were ≥89% similar to REDP 3 or REDP 7 were identified among the farm R isolates. Additionally, the REDP of an O157:H7 isolate from a heifer on farm R in 1994 was indistinguishable from REDP 3. Farm X had one O157:H7 strain that predominated (96% of positive samples had strains with REDP 9), and the REDP of an isolate from a heifer in 1994 was indistinguishable from REDP 9. These results suggest that E. coli O157:H7 is disseminated from a common source on farms and that strains can persist in a herd for a 2-year period.     

Longitudinal Movement and Loss of Nutrients, Pesticides, and Water in Barley Roots

Segments of the roots of young, intact barley plants were treatedin solution culture with labelled nutrients, pesticides, andtritiated water (THO). Some of the labelled substances takenup were lost to the unlabelled solutions surrounding the remainderof the root system. The magnitude of this longitudinal movementand subsequent loss has been compared for phosphate, calcium,and nitrate, for the pesticides simazine and ethirimol, andfor THO. Losses of phosphate and calcium at a distance of 5mm from the treated segments were very small by comparison withthe amounts translocated to the shoots and did not appear tobe greater towards the basal than towards the apical portionof the root system when the labelled solutions were appliedto the middlle segments. There was a larger loss of nitrateand there was some suggestion that this loss was polar, beinggreater in a basipetal direction than towards the root tip.Losses of the two pesticides and in particular of THO were stronglypolar and sufficiently great that over a peried of 24 h onlysmall amounts of these substances which had been taken up bythe apical zones of the roots were translocated to the shoots.The polarity of longitudinal movement and loss of THO was stillvery marked even when transpiration was eliminated by removingthe shoots. Some consideration is given to the possibility ofthe existence of contrasting pathways of movement for the differentsubstances.     

Physical Activity and Bone Mineral Accrual in Boys with Different Body Mass Parameters during Puberty: A Longitudinal Study

The aim of our longitudinal study was to investigate the relationships between physical activity and bone mass in boys with different body mass status during the years surrounding pubertal growth spurt. Two hundred and six boys entering puberty took part in this study. The subjects were divided into underweight (), normal weight (), overweight () and obese () groups at baseline according to age related categories. Whole-body DXA scans were performed at baseline, after 12 and 24 months to assess body composition (lean body mass, fat mass), and total body (TB), lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) parameters. Physical activity was measured by 7- day accelerometry. For longitudinal analysis, multilevel fixed effects regression models were constructed. Biological age, height and lean body mass had an effect for explanation of TB BMD, FN BMD and LS BMD. Moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA) and sedentary time (SED) had the significant effect only on FN BMD. Being an underweight boy at the baseline indicated greater chance (p<0.01) to have lower TB BMD in the future (2 years at follow up) development, compared to normal weight (estimates = −0.038), overweight (estimates = −0.061) and obese boys (estimates = −0.106).     

Symptoms and Quality of Life in Late Stage Parkinson Syndromes: A Longitudinal Community Study of Predictive Factors

Background

Palliative care is increasingly offered earlier in the cancer trajectory but rarely in Idiopathic Parkinson''s Disease(IPD), Progressive Supranuclear Palsy(PSP) or Multiple System Atrophy(MSA). There is little longitudinal data of people with late stage disease to understand levels of need. We aimed to determine how symptoms and quality of life of these patients change over time; and what demographic and clinical factors predicted changes.

Methods

We recruited 82 patients into a longitudinal study, consenting patients with a diagnosis of IPD, MSA or PSP, stages 3–5 Hoehn and Yahr(H&Y). At baseline and then on up to 3 occasions over one year, we collected self-reported demographic, clinical, symptom, palliative and quality of life data, using Parkinson''s specific and generic validated scales, including the Palliative care Outcome Scale (POS). We tested for predictors using multivariable analysis, adjusting for confounders.

Findings

Over two thirds of patients had severe disability, over one third being wheelchair-bound/bedridden. Symptoms were highly prevalent in all conditions - mean (SD) of 10.6(4.0) symptoms. More than 50% of the MSA and PSP patients died over the year. Over the year, half of the patients showed either an upward (worsening, 24/60) or fluctuant (8/60) trajectory for POS and symptoms. The strongest predictors of higher levels of symptoms at the end of follow-up were initial scores on POS (AOR 1.30; 95%CI:1.05–1.60) and being male (AOR 5.18; 95% CI 1.17 to 22.92), both were more predictive than initial H&Y scores.

Interpretation

The findings point to profound and complex mix of non-motor and motor symptoms in patients with late stage IPD, MSA and PSP. Symptoms are not resolved and half of the patients deteriorate. Palliative problems are predictive of future symptoms, suggesting that an early palliative assessment might help screen for those in need of earlier intervention.     

Correlations Between Predominant Heterotrophic Bacteria and Physicochemical Water Quality Parameters in Two Canadian Rivers

The heterotrophic bacterial populations in two contrasting rivers have been examined over a period of 1 year. The populations were analyzed (i) as total heterotrophic counts, (ii) as species numbers, using numerical taxonomy, (iii) by diversity indices, and (iv) by factor analysis. Isolates were obtained by plating directly from water samples and by chemostat enrichment. Four factors emerged which profiled the bacterial community and were common to both rivers. They were, in order of decreasing importance, fermentative metabolism, inorganic nitrogen metabolism, fluorescence-oxidative metabolism, and lack of starch hydrolysis. Several factors produced significant correlations with a range of physicochemical parameters, which were also measured. The correlations suggested an intricate algal-bacterial interaction. The oxidative metabolism factor correlated with rainfall in one river, suggesting that the oxidative bacteria may be washed in from the surrounding land. In the other river, the oxidative-fermentative factor correlated negatively with sunshine. Factor analysis was the most effective method for revealing correlations between bacterial characteristics and the environmental parameters; however, the use of a variety of methods provided more insight into the ecological aspects.     

Longitudinal Study of Intraindividual Variability in Integral Parameters of the Structure Function of Multichannel EEG

Human Physiology - The aim of the work was to assess the stability (intraindividual variability) of two integral parameters of the human EEG, which characterize its spatial and temporal order in a...     

Depression,Inflammation, and Physiological Risk in Late Life: A National Longitudinal Study

This nationally representative study queried effects of community dwelling older adults’ depression and inflammation at baseline on over-time changes in surrogate markers of their cardiometabolic risk. Data were from the 2005–2006 and 2010–2011 waves of the U.S. National Social Life, Health, and Aging Project. Inflammation was indicated by C-reactive protein and depression by the CES-D scale. Cardiometabolic markers included hemoglobin A1c and systolic BP. Lagged dependent variable models were used to examine effects. In none of the models did Wave 1 depression predict residual change in cardiometabolic states (i.e., Wave 2 values net of Wave 1). In contrast, men’s baseline C-reactive protein predicted their Wave 2 hemoglobin A1c (Coeff. = 0.02, p < .05) as well as their systolic BP (Coeff. = 3.22, p < .05). No such effects were found among women. Contrary to a growing clinical literature, depression may not increase cardiometabolic risk among older adults on average. Moderators that may interact with depression to yield such effects in delimited samples remain to be identified. Inflammation, in contrast, does seem linked to increase in physiological risk—but only among men, not women. Clinical research is needed to identify biological factors responsible for this sex difference.     

Assessment of Water Quality of Soan River using Physicochemical Parameters and Aquatic Insects Diversity

Biology Bulletin - In the present study, the effect of pollutants produced by human dwelling, agricultural and industrial activities on aquatic invertebrate’s communities of Soan River,...