207,685 research outputs found

    Impact of Deferral for Low Hemoglobin on Donor Return

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    Introduction. A consistent blood supply to support life-saving transfusions relies on regular and repeat volunteer blood donations. In this study, we focused on donors previously deferred for low-hemoglobin (Hb) levels to better understand the value of supplying post-deferral educational information, and the actions donors took based on their deferral. Methods. An anonymous national survey of active and inactive donor groups (10,000 each) was conducted. The survey questions assessed post-deferral donor actions, preferences regarding post deferral education, understanding of their deferral, and demographic information. Chi-square analysis was performed to compare categorical survey results between donor groups with p \u3c 0.05 denoting statistical significance. Results. The survey resulted in 722 and 103 active and inactive donor respons- es, respectively. Active donors were more likely to recall receiving educational materials post-deferral (52% vs. 35%, p=003), take iron and vitamin supplements (54% vs. 39%, p=0.009), lived within 30 min of a donor site (94% vs. 84%, p=0.006), and more likely to be older than 45 yr (62% vs. 42%, p=0.002) than their inactive donor counter- parts. Active and inactive donors were similar (p\u3e0.05) with anemia history frequency, female-gender predominance, low-prevalence of vegans, and mixed interest in receiving information about raising hemoglobin levels. Conclusion. While active donors more frequently recalled receiving educational materials for their low hemoglobin deferral, and were more likely to take action to improve their hemoglobin, an alternative method of post-deferral recruitment should be considered given the uncertain value of post-deferral information when comparing active vs. inactive donors.https://scholarworks.uvm.edu/comphp_gallery/1253/thumbnail.jp

    Effects of drinking-water filtration on Cryptosporidium Seroepidemiology, Scotland

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    Continuous exposure to low levels of Cryptosporidium oocysts is associated with production of protective antibodies. We investigated prevalence of antibodies against the 27-kDa Cryptosporidium oocyst antigen among blood donors in 2 areas of Scotland supplied by drinking water from different sources with different filtration standards: Glasgow (not filtered) and Dundee (filtered). During 2006–2009, seroprevalence and risk factor data were collected; this period includes 2007, when enhanced filtration was introduced to the Glasgow supply. A serologic response to the 27-kDa antigen was found for ≈75% of donors in the 2 cohorts combined. Mixed regression modeling indicated a 32% step-change reduction in seroprevalence of antibodies against Cryptosporidium among persons in the Glasgow area, which was associated with introduction of enhanced filtration treatment. Removal of Cryptosporidium oocysts from water reduces the risk for waterborne exposure, sporadic infections, and outbreaks. Paradoxically, however, oocyst removal might lower immunity and increase the risk for infection from other sources

    Correlated Doping in Semiconductors: The Role of Donors in III-V Diluted Magnetic Semiconductors

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    We investigate the compositional dependence of the total energy of the mixed crystals (Ga,Mn)As co-doped with As, Sn, and Zn. Using the ab initio LMTO-CPA method we find a correlation between the incorporation of acceptors (Mn, Zn) and donors (Sn, antisite As). In particular, the formation energy of As_Ga is reduced by approx. 0.1 eV in the presence of Mn, and vice versa. This leads to the self-compensating behavior of (Ga,Mn)As.Comment: 8 pages, 2 figures, presented at the XXXI Int. School of Semiconducting Compounds, Jaszowiec 2002, Polan

    Ethical and methodological dilemmas in mixed-methods research: an empirically-based perspective about gamete donation

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    Research in the field of gamete donation has focused mostly on the dichotomy between the resource-poor countries/conditions of the donors and the richer Western countries’ recipients/hosting research projects. Furthermore, most independent studies focus only on the group of donors, with a shortage of original empirical research using mixed-methods. Based on a mixed-methods study that aims to understand how social, cultural and economic characteristics intertwine with the health experiences, knowledge and identities of those involved in gamete donation (i.e. donors, recipients and health professionals), we will explore the ethical and methodological challenges that emerged in connection to fieldwork experiences associated with anonymity, confidentiality, informed consent, researchers’ gender and researchers’ potential impact on the participant and vice versa.info:eu-repo/semantics/publishedVersio

    Pollen competitive ability: the effect of proportion in two-donor crosses

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    Pollen competitive ability depends on the innate capacity of a pollen donor to produce pollen that reaches the ovules fast, but could also be a consequence of the ability to interfere with pollen from other donors. In a greenhouse study on Viola tricolor, we examined the relative importance of both of these effects by performing crosses where we varied the pollen load composition of two donors. We found that when a pollen donor had higher in vitro pollen tube growth rate than a competitor, this donor sired proportionally more seeds in most cases. At very low proportions, however, there was no benefit of producing fast growing pollen. We further investigated the potential for pollen interactions by comparing in vitro performance in single- and mixed-donor batches of the same density. Pollen tube growth rate differed between treatments in some donor combinations, indicating that pollen from different donors interact. Only donors with the faster growing pollen tubes in the single samples showed signs of interference in the mixtures. Donors with slower pollen tube growth had an increased growth rate when mixed. Although our results suggest interactions between pollen grains from different donors that might affect siring ability, the intrinsic pollen tube growth rate was more important for siring ability in this species

    Impression Management and Psychological Reactions of Living Kidney Donors

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    This report describes the findings of a mixed-methods study that examined the psychological reactions and use of impression management by individuals who had donated a kidney. It focused on the use of impression management and concealing information during the pre-donation psychological evaluation that is conducted to help determine the donor’s appropriateness for a donation, and the psychological reactions of living kidney donors post donation. A search of the literature found no study that has empirically investigated the prevalence of impression management and concealing information by living kidney donors during their pre-donation psychosocial evaluations. The mixed methods design utilized both a quantitative phone questionnaire (n= 76) as well as qualitative focus groups (n=21). Many of the kidney donors reported that they used impression management in their interactions with medical professionals pre-donation as they often possessed a very strong motivation to donate. Very few donors indicated, however, that they concealed information during their pre-donation evaluations. The donors’ psychological reactions post-donation were generally positive and the very large majority indicated that they had no regrets concerning donation. Some negative psychological reactions were reported, though these tended to be associated with kidney grafts that were unsuccessful

    Janus Scorpionates:  Supramolecular Tectons for the Directed Assembly of Hard−Soft Alkali Metallopolymer Chains

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    A new scorpionate ligand [HB(mtda)3-] containing mercaptothiadiazolyl (mtda) heterocyclic rings with both hard nitrogen donors and soft sulfur donors has been prepared. This new ligand, the Janus scorpionate, is a hybrid of a tris(pyrazolyl)borate and a tris(mercaptoimidazolyl)borate. The differential hard/soft character of the dissimilar donor groups in this bridging ligand was exploited for the controlled solid-state organization of homometallic and heterometallic alkali metal coordination polymers. Remarkably, in the case of sodium, coordination polymers with both acentric (with NaS3N3H kernels) and centric (with alternating NaN6 and NaS6H2 kernels) chains are found in the same crystal (where the centricity is defined by the relative orientations of the B−H bonds of the ligands along the lattice). For the homometallic potassium congener, the larger cation size, compared to sodium, induced significant distortions and favored a polar arrangement of ligands in the resulting coordination polymer chain. An examination of the solid-state structure of the mixed alkali metal salt system revealed that synergistic binding of smaller sodium cations to the nitrogen portion and of the larger potassium cations to the sulfur portion of the ligand minimizes the ligand distortions relative to the homometallic coordination polymer counterparts, a design feature of the ligand that likely assists in thermodynamically driving the self-assembly of the heterometallic chains. The effect of alkali metal complexation on the solution properties of the ligand was studied by comparing NMR chemical shifts, B−H stretching frequencies, and electrochemical properties with those of the noncoordinating tetrabutylammonium salt of the scorpionate. The similarity of these data regardless of cation indicates that the salts are likely dissociated in solution rather than maintaining their solid-state polymeric structures. This data is augmented by the ESI(±) mass spectral data for a series of mixed alkali metal tris(mercaptothiadiazolyl)borates that also indicate that dissociation occurs in solution

    The impact of face-to-face street fundraising on organizational reputation

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    Although many stakeholders perceive face-to-face street fundraising as unpleasant, nonprofit managers encourage it as a way to attract donors. To understand the long-term effects of this fundraising method, we used a mixed-methods experimental design to investigate how face-to-face street fundraising affects organizational reputation and stakeholder support intentions in comparison with letter fundraising. The findings reveal that face-to-face street fundraising has a significant negative influence on the stakeholders' perceptions of an organization. Further, qualitative datashow that the negative perception originates primarily from perceived pressure, distrust, and obtrusion, which are triggered by face-to-face street fundraising. Our studythus reveals long-term reputational consequences that nonprofit organizations should consider before deciding on fundraising methods

    Hepatitis C virus infection in blood donors from the state of Puebla, Mexico

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    <p>Abstract</p> <p>Background</p> <p>Worldwide, 130 million persons are estimated to be infected with HCV. Puebla is the Mexican state with the highest mortality due to hepatic cirrhosis. Therefore, it is imperative to obtain epidemiological data on HCV infection in asymptomatic people of this region. The objective of present study was to analyze the prevalence of antibodies and genotypes of hepatitis C virus (HCV) in blood donors from Puebla, Mexico.</p> <p>Results</p> <p>The overall prevalence was 0.84% (515/61553). Distribution by region was: North, 0.86% (54/6270); Southeast, 1.04% (75/7197); Southwest, 0.93% (36/3852); and Central, 0.79% (350/44234). Ninety-six donors were enrolled for detection and genotyping of virus, from which 37 (38.5%) were HCV-RNA positive. Detected subtypes were: 1a (40.5%), 1b (27.0%), mixed 1a/1b (18.9%), undetermined genotype 1 (5.4%), 2a (2.7%), 2b (2.7%), and mixed 1a/2a (2.7%). All recovered donors with S/CO > 39 were HCV-RNA positive (11/11) and presented elevated ALT; in donors with S/CO < 39 HCV-RNA, positivity was of 30.4%; and 70% had normal values of ALT. The main risk factors associated with HCV infection were blood transfusion and surgery.</p> <p>Conclusions</p> <p>HCV prevalence of donors in Puebla is similar to other Mexican states. The most prevalent genotype is 1, of which subtype 1a is the most frequent.</p
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