1,714 research outputs found
The Influence of Hiking Trails on Salamanders
Over half of the Worldâs salamanders are facing extinction. It is important to understand the impact Humans have on them in all parts of their ranges so we can better understand what they need and how we can prevent further extinctions. I conducted this study to try to determine if the human activity on the official hiking trails in the Arcata Community Forest in Arcata California; as designated by the official map of the Forest; is negatively impacting the salamanders that live in the Forest. I thought there would be an increase in the number of species and the overall number of salamanders as the plots got further away from the hiking trails. I conducted area constrained searches to examine the individual abundance and species diversity of salamanders in the Arcata Community Forest to their distance from the hiking trails. I also examined the correlation between the salamanders weight and snout-vent length to the distance from the trail the salamanders were found at. The salamanders were located and measured using a series of area constrained searches inside 1x1 meter plots, with a distance of at least 20 meters between them. The plots covered an area from 0 to 11 meters away from the trail. The salamanders were bagged, identified to species, then weighed and measured from their snout to their vent. The data was analyzed using Spearmanâs Rank Correlation analyses and used t-values to determine the significance of the correlations. The p-values for the Spearmanâs Rank Correlations for the species number to the distance from the trail and the number of individual salamanders to the distance from the trail both came back as having significant correlations with higher numbers of species and individuals closer to the trails. This could mean the trails are acting as ecological traps for the salamanders, so the trails and their associated human activities may still be harming the salamanders, despite the salamanders seemingly being drawn to the trails instead of staying away from them like I thought they would. Follow up studies are needed to determine if this is a case of an ecological trap
Exploring the Pharmacophore of Novel Synthetic Peptide Activators of type I-alpha cGMP-Dependent Protein Kinase
cGMP-dependent protein kinase (PKG, cGPK) is a serine-threonine kinase of the AGC-kinase family. Although PKG type Ia plays a prominent role in the control of blood-flow and blood pressure, no current hypertension therapies target this enzyme.1 A PKG-targeted therapy would establish a first-in-class treatment for patients with uncontrolled blood pressure and may provide a clinically relevant alternative to existing antihypertensive therapies.
Dostmann et al. developed novel peptides derived from the crystal structure of PKG Ia, which are helical in solution and found to activate the kinase independent of cGMP and were demonstrated to lower blood pressure in vivo.2,3 Two consecutive phenylalanine residues were identified as a central element of the putative pharmacophore within the full-length peptide. However, a shortened peptide derivative, called S1.5 (here SP), was found to have increased potency and thus has been suggested as a potential lead compound for further development. The aim of this thesis is to reevaluate the pharmacophore and specifically the role of the phenylalanine residues in context of the SP peptide.
In this study, analogs of SP were designed using an alanine-scanning approach to analyze the role of specific amino acids in the activation mechanism. By employing recombinant PKG Ia, kinetic parameters were determined using a specific radiometric assay.4,5
We found that substituting either or both phenylalanine residues for alanine did not impair the peptideâs potency or efficacy. However, deleting one phenylalanine greatly diminished activity. This phenotype could be rescued by substituting either of two positively charged lysine residues N-terminal to the pharmacophore for alanine. These results indicate that the interactions between the kinase and these novel synthetic peptides are more complex and involve unidentified amino acids. Furthermore, the results presented here will serve to evaluate the role of N-terminal residues in peptide binding and the rescue phenotype discovered in this study
A Future Without Spectacle: A Refuge from Cultural Hegemony in Contemporary Art and Neo-Humanism
Abstract This paper explores possibilities for the future of popular culture. Central to the arguments in this paper, is the search for a remedy to a visual culture that has been left deconstructed and fragmented by a Western obsession with postmodernism. This paper begins with a discussion of Boris Groyâs âsociety of spectacle without spectatorsâ (2012) and the ramifications of such an observation as homological to the state of contemporary art and the human subject. A discussion of the works of modern and contemporary artists is used to illustrate contemporary artâs metonymic relationship to the future of popular culture. Specific examples are explored such as German photographer and film maker Thomas Demandâs works that create a âcritical fictionâ Liljegren (2013) to highly engage the spectator and are juxtaposed with postmodern speculations such as Baudrillardâs simulacra
Predictors of survival in a cohort of patients with polymyositis and dermatomyositis: effect of corticosteroids, methotrexate and azathioprine
Introduction: The idiopathic inflammatory myopathies are rare diseases for which data regarding the natural
history, response to therapies and factors affecting mortality are needed. We performed this study to examine the
effects of treatment and clinical features on survival in polymyositis and dermatomyositis patients.
Methods: A total of 160 consecutive patients (77 with polymyositis and 83 with dermatomyositis) seen at the
University of Michigan from 1997 to 2003 were included. Medical records were abstracted for clinical, laboratory
and therapeutic data, including initial steroid regimen and immunosuppressive use. State vital records were utilized
to derive mortality and cause of death data. Survival was modeled by left-truncated Kaplan-Meier estimation and
Cox regression.
Results: The 5- and 10-year survival estimates were 77% (95% CI = 66 to 85), and 62% (95% CI = 48 to 73),
respectively, and the rates were similar for polymyositis and dermatomyositis. Survival between the sexes was
similar through 5 years and significantly lower thereafter for males (10-year survival: 18% male, 73% female; P =
0.002 for 5- to 10-year interval). The sex disparity was restricted to the polymyositis group. Increased age at
diagnosis and non-Caucasian race were associated with lower survival. Intravenous versus oral corticosteroid use
was associated with a higher risk of death among Caucasians (HR = 10.6, 95% CI = 2.1 to 52.8). Early survival
between patients treated with methotrexate versus azathioprine was similar, but survival at 10 years was higher for
the methotrexate-treated group (76% vs 52%, P = 0.046 for 5- to 10-year interval).
Conclusions: Patients treated initially with intravenous corticosteroids had higher mortality, which was likely
related to disease severity. Both methotrexate and azathioprine showed similar early survival benefits as first-line
immunosuppressive drugs. Survival was higher between 5 and 10 years in the methotrexate-treated group, but
could not be confirmed in multivariable modeling for the full follow-up period. Other important predictors of longterm
survival included younger age, female sex and Caucasian race.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90025/1/IIM_ART2012.pdf1611
A Pilot Study of Methylphenidate Preference Assessment in Children Diagnosed with Attention-Deficit/Hyperactivity Disorder
Objective: The use of methylphenidate (MPH) in the treatment of attention-deficit/hyperactivity disorder (ADHD) is widely accepted; however, there is increased concern regarding its abuse potential. Few studies have examined the reinforcing effects of drugs in individuals receiving them for clinical purposes. This study attempts to assess MPH preference in children with ADHD using a choice procedure in order to explore the relationship among drug preference, clinical efficacy, and abuse potential. Methods: Participants were 5 children (10â14 years of age) receiving MPH for the treatment of ADHD. Reinforcing effects were assessed using a double-blind choice procedure, with six sampling sessions and six choice sessions. Participant-rated effects were measured using self-report questionnaires. Clinical effects were measured using direct observations and behavior ratings. Results: Differences between the number of MPH, Placebo, and Neither choices across participants were significant (X 2 = 9.6; p < 0.01). Three of five participants reliably chose MPH more often than placebo. MPH produced idiosyncratic patterns of participant-rated effects but failed to produce significant clinical effects. Conclusions: These findings add to the literature on the reinforcing effects of MPH and are the first reported in a clinical sample of children. Further research exploring the role of clinical efficacy in MPH preference is warranted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63388/1/cap.2005.15.729.pd
Understanding the phosphoric acid catalysed ring opening polymerisation of ÎČ-Butyrolactone and other cyclic esters
An Expanded Range of Catalysts for Synthesizing Biodegradable Polyphosphonates
In this paper we expand the scope of catalysts able to mediate the ring opening polymerisation of the phosphonate monomer 2-methyl-1,3,2-dioxaphosphalone-2-oxide. A range of nitrogen bases efficiently catalyse the reaction, each with pK as of 19 or above; lower pK a bases do not ring open the monomer. Aluminium based catalysts supported by salen and salan ligand frameworks also afford exceptional control, with conversions in excess of 99% and dispersities under 1.1. Together, these studies significantly expand the scope of catalysts to prepare this biodegradable, non-toxic, water soluble polymer. Additionally, we report efforts to expand the monomer scope for these catalysts, showing that altering ring structure and substitution can strongly inhibit productive ring opening. </jats:p
Eyes Toward the Future: Framing For-credit Information Literacy Instruction
LSU Libraries recently redesigned its one-credit hour information literacy course taught by librarians for undergraduate students. This redesign coincided with a shift from face-to-face to online course delivery at a local level alongside the implementation of the Universityâs Quality Enhancement Plan (QEP) on undergraduate research that would lead to increased course enrollment at the university level. At the national level, there was a transition to ACRLâs Framework for Information Literacy for Higher Education (Framework). The Librariesâ Instruction Committee engaged in a holistic reconceptualization of the course, beginning with debating and designing new student learning outcomes (SLOs) and attributes before considering content and assessment. Although for-credit courses provide librarians with an avenue to impact information literacy growth more deeply than a single instruction session (commonly referred to as a âone-shotâ), these courses are increasingly rare. Nonetheless, the Framework represents an opportunity for librarians to redesign existing instruction on small and large scale
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