111 research outputs found
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The Social Behavior and Dynamics of Old Ring-Tailed Lemurs (Lemur Catta) at the Duke Lemur Center
There has been little emphasis within primatology on the social and behavioral strategies old primates might use to meet the challenges of senescence while maintaining social engagement, such as assuming a group role like navigator. Understanding how old primates maintain sociality can reveal how behavioral flexibility might have facilitated an increase in longevity within the order. Using focal sampling of old (N = 9, 10+ years) and adult (N = 6, <10 years) Lemur catta at the Duke Lemur Center, activity budgets, social interactions, and group traveling information were recorded and compared from May to August of 2016. I found that both male and female old lemurs maintained sociality in the group, with older females being more social than adults. I failed to support the second hypothesis that older individuals would have a behavioral profile distinct from adults. Finally, I found preliminary support that older females help care for a daughter’s offspring in the form of carrying. These results indicate that social manifestations of age and senescence depend on a myriad of factors such as environment, life history, and individual personalities. This research also reveals the importance of decoupling ideas of chronological age, being an old individual, with senescence because somatic decline depends on these other factors besides age. Understanding these complex interactions is essential as we strive to define senescence and explore how age has shaped evolutionary trajectories among primates.</p
Immediate Versus Delayed Insertion of the Levonorgestrel Intrauterine Device in Postpartum Adolescents: A Randomized Pilot Study.
This pilot study assessed the feasibility of conducting a larger randomized controlled trial comparing the proportion of adolescents using a levonorgestrel intrauterine device (LNG IUD) at six months postpartum when it is inserted immediately after vaginal delivery (within 10 minutes after placental expulsion) compared to insertion four to six weeks postpartum. Pregnant adolescents (14 to 19 years) who desired a LNG IUD for postpartum contraception were randomized to insertion of the LNG IUD either within 10 minutes of delivery of the placenta or at 4-6 weeks postpartum. Study follow-up visits were conducted at 4-6 weeks postpartum, 10 weeks postpartum, and 6 months postpartum. From November 2013 to June 2015, eleven adolescents were randomized - six participants to the immediate postpartum LNG IUD insertion group, and five to the delayed insertion group. All six women in the immediate insertion group had successful immediate postpartum insertion; two of five women in the delayed insertion group had an IUD inserted. At six months postpartum, four of six women in the immediate insertion group had a LNG IUD in place; of the five women in the delayed group, three did not have a LNG IUD in place and two were pregnant. The study was discontinued after 19 months because of suboptimal enrollment. Though insertion of a LNG IUD immediately after delivery is an appropriate option for some adolescents, a larger prospective study comparing immediate to delayed LNG IUD insertion is unlikely to be feasible at our institution
Students’ Attitudes and Perceptions toward Interprofessional Education
Three scales were administered to measure attitudes of graduate students in health professions prior to their participation in an interprofessional education (IPE) pilot program. Overall, results indicated that students’ attitudes toward IPE were generally positive, but there is room for improvement. Additionally, medical students’ attitudes differed from the other disciplines
Prevalence and Impact of Dysmenorrhea Among University Students in Ireland
Objective Primary dysmenorrhea (PD), or painful menstruation, is a common gynecological condition that can cause intense pain and functional disability in women of reproductive age. As a nonmalignant condition, PD is relatively understudied and poorly managed. The purpose of this study was to estimate the prevalence and impact of PD among third-level students in Ireland. Design A cross-sectional observational design was used. Methods Students (n = 892; age range = 18–45 years) completed an online survey on menstrual pain characteristics, pain management strategies, pain interference, and pain catastrophizing. Results The prevalence of PD was 91.5% (95% confidence interval = 89.67–93.33). Nonpharmacological management strategies were most popular (95.1%); of these, heat application (79%), rest (60.4%), hot shower/bath (40.9%), and exercise (25.7%) were most common. Perceived effectiveness of these methods varied between participants. Analgesic use was also common (79.5%); of these, paracetamol was most used (60.5%) despite limited perceived effectiveness. Pain catastrophizing was a significant predictor of variance in both pain intensity and pain interference scores such that those with higher pain catastrophizing scores reported more intense pain and greater interference with daily activities and academic demands. Conclusions This article presents the first investigation into PD among third-level students in Ireland. Poorly managed menstrual pain may impact functional ability across several domains. Future research should focus on improving menstrual pain management education and support and promoting menstrual health literacy for women affected by PD
Pediatric Cancer Genetics Research and an Evolving Preventive Ethics Approach for Return of Results after Death of the Subject
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115941/1/jlme12295.pd
Supramolecular Click Chemistry for Surface Modification of Quantum Dots Mediated by Cucurbit[7]uril
Cucurbiturils (CBs), barrel-shaped macrocyclic molecules, are capable of self-assembling at the surface of nanomaterials in their native state, via their carbonyl-ringed portals. However, the symmetrical two-portal structure typically leads to aggregated nanomaterials. We demonstrate that fluorescent quantum dot (QD) aggregates linked with CBs can be broken-up, retaining CBs adsorbed at their surface, via inclusion of guests in the CB cavity. Simultaneously, the QD surface is modified by a functional tail on the guest, thus the high affinity host-guest binding (logKa > 9) enables a non-covalent, click-like modification of the nanoparticles in aqueous solution. We achieved excellent modification efficiency in several functional QD conjugates as protein labels. Inclusion of weaker-binding guests (logKa = 4-6) enables subsequent displacement with stronger binders, realising modular switchable surface chemistries. Our general "hook-and-eye" approach to host-guest chemistry at nanomaterial interfaces will lead to divergent routes for nano-architectures with rich functionalities for theranostics and photonics in aqueous systems
KOtBu : a privileged reagent for electron transfer reactions?
Many recent studies have used KOtBu in organic reactions that involve single electron transfer; in the literature, the electron transfer is proposed to occur either directly from the metal alkoxide or indirectly, following reaction of the alkoxide with a solvent or additive. These reaction classes include coupling reactions of halobenzenes and arenes, reductive cleavages of dithianes and SRN1 reactions. Direct electron transfer would imply that alkali metal alkoxides are willing partners in these electron transfer reactions, but the literature reports provide little or no experimental evidence for this. This paper examines each of these classes of reaction in turn, and contests the roles proposed for KOtBu; instead, it provides new mechanistic information that in each case supports the in situ formation of organic electron donors. We go on to show that direct electron transfer from KOtBu can however occur in appropriate cases, where the electron acceptor has a reduction potential near the oxidation potential of KOtBu, and the example that we use is CBr4. In this case, computational results support electrochemical data in backing a direct electron transfer reaction
Supramolecular Click Chemistry for Surface Modification of Quantum Dots Mediated by Cucurbit[7]uril
Cucurbiturils (CBs), barrel-shaped macrocyclic molecules, are capable of self-assembling at the surface of nanomaterials in their native state, via their carbonyl-ringed portals. However, the symmetrical two-portal structure typically leads to aggregated nanomaterials. We demonstrate that fluorescent quantum dot (QD) aggregates linked with CBs can be broken-up, retaining CBs adsorbed at their surface, via inclusion of guests in the CB cavity. Simultaneously, the QD surface is modified by a functional tail on the guest, thus the high affinity host-guest binding (logKa > 9) enables a non-covalent, click-like modification of the nanoparticles in aqueous solution. We achieved excellent modification efficiency in several functional QD conjugates as protein labels. Inclusion of weaker-binding guests (logKa = 4-6) enables subsequent displacement with stronger binders, realising modular switchable surface chemistries. Our general “hook-and-eye” approach to host-guest chemistry at nanomaterial interfaces will lead to divergent routes for nano-architectures with rich functionalities for theranostics and photonics in aqueous systems
Towards direct detection of tetracycline residues in milk with a gold nanostructured electrode
Tetracycline antibiotics are used extensively in veterinary medicine, but the majority of the administrated dose is eliminated unmodified from the animal through various excretion routes including urine, faeces and milk. In dairy animals, limits on residues secreted in milk are strictly controlled by legislation. Tetracyclines (TCs) have metal chelation properties and form strong complexes with iron ions under acidic conditions. In this study, we exploit this property as a strategy for low cost, rapid electrochemical detection of TC residues. TC-Fe(III) complexes in a ratio of 2:1 were created in acidic conditions (pH 2.0) and electrochemically measured on plasma-treated gold electrodes modified with electrodeposited gold nanostructures. DPV measurements showed a reduction peak for the TC-Fe(III) complex that was observed at 50 mV (vs. Ag/AgCl QRE). The limit of detection in buffer media was calculated to be 345 nM and was responsive to increasing TC concentrations up to 2 mM, added to 1 mM FeCl3. Whole milk samples were processed to remove proteins and then spiked with tetracycline and Fe(III) to explore the specificity and sensitivity in a complex matrix with minimal sample preparation, under these conditions the LoD was 931 nM. These results demonstrate a route towards an easy-to-use sensor system for identification of TC in milk samples taking advantage of the metal chelating properties of this antibiotic class
Polymorphs and hydrates of acyclovir
Acyclovir (ACV) has been commonly used as an antiviral for decades. Although the crystal structure of the commercial form, a 3:2 ACV/water solvate, has been known since 1980s, investigation into the structure of anhydrous ACV has been limited. Here, we report the characterization of four anhydrous forms of ACV and a new hydrate in addition to the known hydrate. Two of the anhydrous forms appear as small needles and are stable to air exposure, whereas the third form is morphologically similar but quickly absorbs water from the atmosphere and converts back to the commercial form. The high-temperature modification is achieved by heating anhydrous form I above 180°C. The crystal structures of anhydrous form I and a novel hydrate are reported for the first time. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:949–963, 2011Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79417/1/22336_ftp.pd
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