An assessment of the physical, chemical, and biological properties of Christine Lake, NH

As part of a comparative assessment of seven New Hampshire lakes, performed throughout the month of September 2003, students and faculty from the University of New Hampshire’s Center for Freshwater Biology sampled Christine Lake in Stark, NH. The goal of the study was to quantify the lake’s physical, chemical, and biological properties and compare it to the six other lakes studied, as well as to results from identical sampling of Christine Lake in June, 2003. Christine Lake is an oligotrophic lake with very little primary production and low densities of zooplankton. Nutrient levels were low, likely due to the forested composition of the lake’s watershed and the small number of homes on the lake’s shore. The low phosphorus concentration and high N:P ratio (TN:TP = 50) typify a phosphoruslimited system which is likely to be the cause of the minimal algal abundance (1.6 ± 0.1 µg L-1 average epilimnetic chlorophyll compared to 39.4 ± 1.0 µg L-1 in eutrophic York Pond). Predation by young Brook and Brown Trout most likely favored the increased densities of the smaller zooplankter Bosmina (average body length: 0.42 mm ± 0.01), as they are not readily visible to the trout like the larger Daphnia (average body length: 1.39 mm ± 0.03). Evidence for increased predation on Daphnia can be seen in their location in the water column (8 m and 12 m) which indicates migration to deeper waters to avoid fish predation. The depressed density and size of the zooplankton in the lake are most likely due to a lack of suitable grazing material and predation from the planktivorous fish population. Interactions between zooplankton and higher trophic levels, as well as phytoplankton, are discussed in the context of a model food web

Enumerating Colorings, Tensions and Flows in Cell Complexes

We study quasipolynomials enumerating proper colorings, nowhere-zero tensions, and nowhere-zero flows in an arbitrary CW-complex $X$, generalizing the chromatic, tension and flow polynomials of a graph. Our colorings, tensions and flows may be either modular (with values in $\mathbb{Z}/k\mathbb{Z}$ for some $k$) or integral (with values in $\{-k+1,\dots,k-1\}$). We obtain deletion-contraction recurrences and closed formulas for the chromatic, tension and flow quasipolynomials, assuming certain unimodularity conditions. We use geometric methods, specifically Ehrhart theory and inside-out polytopes, to obtain reciprocity theorems for all of the aforementioned quasipolynomials, giving combinatorial interpretations of their values at negative integers as well as formulas for the numbers of acyclic and totally cyclic orientations of $X$.Comment: 28 pages, 3 figures. Final version, to appear in J. Combin. Theory Series

Therapeutic relationships in day surgery: a grounded theory study

Aim: The aim of the study was to explore patients’ experiences of day surgery. Background: Therapeutic relationships are considered to be a core dimension of nursing care. However in modern healthcare with short hospital stays the formation of these relationships may be impeded. A major theme to emerge from this study was the development of therapeutic relationships in the day surgery setting. Methodology: The Glaserian method of Grounded Theory was utilised. Semi –structured interviews with 145 patients took place from 2004-2006 in two day surgery units in the United Kingdom. Analysis involved transcriptions of interviews and memos. Lists of key words and phrases were made and constantly compared until core categories began to emerge. Results: Patients spoke highly of the relationships they developed with nurses during their stay in the day surgery unit. Analysis of the data revealed the core category of therapeutic relationships and four sub core categories: “presence,” “extra special” “befriending” and “comfort-giving.” Conclusion: This paper adds to the growing body of literature which demonstrates that therapeutic relationships can be developed within the short stay arena of health care : routine interactions which may not be considered to be significant by nurses may be of importance to patients. The patients in this study felt supported, comforted and befriended by day surgery nurses. However a minority of patients were disappointed with the nursing staff responses to patient needs. Relevance to clinical practice: Anecdotal and empirical evidence suggests that personnel working within day surgery are not always aware of their therapeutic potential. Therefore raising awareness of this through research generated from patients’ experiences might encourage nurses to further realise their capabilities in this fundamental area of nursing

Herd characteristics and cow-level factors associated with Prototheca mastitis on dairy farms in Ontario, Canada

Prototheca spp. are algae that cause incurable acute or chronic mastitis in dairy cows. The aim of this case-control study was the identification of cow- and herd-level risk factors for this unusual mastitis pathogen. Aseptically collected composite milk samples from 2,428 milking cows in 23 case and 23 control herds were collected between January and May 2011. A questionnaire was administered to the producers, and cow-level production and demographic data were gathered. In 58 of 64 isolates, Prototheca spp. and Prototheca zopfii genotypes were differentiated using PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. All isolates were identified as Prototheca zopfii genotype 2. The mean within-herd prevalence for Prototheca spp. was 5.1% (range 0.0-12.5%). Case herds had a significantly lower herd-level prevalence of Staphylococcus aureus and a higher prevalence of yeasts than did control herds. The final logistic regression model for herd-level risk factors included use of intramammary injections of a non- intramammary drug [odds ratio (OR) = 136.8], the number of different injectable antibiotic products being used (OR = 2.82), the use of any dry cow teat sealant (external OR = 80.0; internal OR = 34.2), and having treated 3 or more displaced abomasums in the last 12 mo OR = 44.7). The final logistic regression model for cow-level risk factors included second or greater lactation (OR = 4.40) and the logarithm of the lactation-average somatic cell count (OR = 2.99). Unsanitary or repeated intramammary infusions, antibiotic treatment, and off-label use of injectable drugs in the udder might promote Prototheca udder infection

A Conceptual Analysis

Johne’s disease (JD) is a chronic, production-limiting disease of ruminants. Control programs aiming to minimize the effects of the disease on the dairy industry have been launched in many countries, including Canada. Those programs commonly focus on strict hygiene and management improvement, often combined with various testing methods. Concurrently, organic dairy farming has been increasing in popularity. Because organic farming promotes traditional management practices, it has been proposed that organic dairy production regulations might interfere with implementation of JD control strategies. However, it is currently unclear how organic farming would change the risk for JD control. This review presents a brief introduction to organic dairy farming in Canada, JD, and the Canadian JD control programs. Subsequently, organic practices are described and hypotheses of their effects on JD transmission are developed. Empirical research is needed, not only to provide scientific evidence for organic producers, but also for smaller conventional farms employing organic-like management practices

The Influence of IL-10 and TNFα on Chondrogenesis of Human Mesenchymal Stromal Cells in Three-Dimensional Cultures

Chondrogenic differentiated mesenchymal stromal cells (MSCs) are a promising cell source for articular cartilage repair. This study was undertaken to determine the effectiveness of two three-dimensional (3D) culture systems for chondrogenic MSC differentiation in comparison to primary chondrocytes and to assess the effect of Interleukin (IL)-10 and Tumor Necrosis Factor (TNF)α on chondrogenesis by MSCs in 3D high-density (H-D) culture. MSCs were isolated from femur spongiosa, characterized using a set of typical markers and introduced in scaffold-free H-D cultures or non-woven polyglycolic acid (PGA) scaffolds for chondrogenic differentiation. H-D cultures were stimulated with recombinant IL-10, TNFα, TNFα + IL-10 or remained untreated. Gene and protein expression of type II collagen, aggrecan, sox9 and TNFα were examined. MSCs expressed typical cell surface markers and revealed multipotency. Chondrogenic differentiated cells expressed cartilage-specific markers in both culture systems but to a lower extent when compared with articular chondrocytes. Chondrogenesis was more pronounced in PGA compared with H-D culture. IL-10 and/or TNFα did not impair the chondrogenic differentiation of MSCs. Moreover, in most of the investigated samples, despite not reaching significance level, IL-10 had a stimulatory effect on the type II collagen, aggrecan and TNFα expression when compared with the respective controls

Jangle Fallacy: Is Grit Distinct from Other Psychological Constructs?

This paper assessed the redundancy of the construct of grit (Crede, Tynan, Harms, 2017) compared to other similar constructs using structural equation modeling to remove the effect of measurement error. A series of models regressed grit and its subdomains (passion and perseverance of effort) on self-control, conscientiousness, achievement striving, and resilience. The R-squared values for these models ranged from 0.62 to 0.89. It is concluded that the concept of grit is mostly redundant with other constructs and is therefore an example of a Jangle fallacy (Kelley, 1927). The unique aspect of grit is mostly related to its passion subdomain. The latent correlation between the passion and perseverance of effort subdomains was r = 0.19. Further, it was found that several popular measures failed to conform to their intended factor structure

Individual Characteristics of Postsecondary Underachievement

Underachievement in postsecondary education has been a growing concern for educators and researchers. Higher education institutions have implemented early alert systems to identify students performing below standards. This early warning system has major limitations that confine it to an identification only approach. The current study aimed to investigate the psychometric properties of the Student Attitude Assessment Survey-R (SAAS-R) in a postsecondary sample. First, a confirmatory factor analysis validated the SAAS-R in a postsecondary sample. Predictive validity was then investigated by identifying students as underachieving or achieving based on responses to the SAAS-R and via a regression-based discrepancy model (ability vs. achievement). Then, the SAAS-R was compared to the discrepancy model to see whether the SAAS-R is an accurate assessment for identification of achievement. Tests of convergent validity included comparison of the SAAS-R subscales to well established similar constructs. Discriminant validity was checked by comparing the SAAS-R to a Social Desirability Scale. Finally, measurement invariance was explored to see if the SAAS-R would measure across groups. The SAAS-R demonstrated strong evidence of structural, convergent, and discriminant validity, yet limited evidence of predictive validity. Assessment of measurement invariance across self-identified traditional and non-traditional students yielded no evidence of measurement invariance. Initial psychometric properties support extension of the structural model of the SAAS-R to postsecondary students and the convergent validity utility of the SAAS-R subscales. However, more research is needed before the SAAS-R can be applied as an assessment of underachievement in postsecondary education