Nutzung von MPI für parallele FEM-Systeme

Der Standard des Message Passing Interfaces (MPI) stellt dem Entwickler paralleler Anwendungen ein mächtiges Werkzeug zur Verfügung, seine Softwa- re effizient und weitgehend unabhängig von Details des parallelen Systems zu entwerfen. Im Rahmen einer Projektarbeit erfolgte die Umstellung der Kommunikationsbibliothek eines bestehenden FEM-Programmes auf den MPI-Mechanismus. Die Ergebnisse werden in der hier gegebenen Beschreibung der Cubecom-Implementierung zusammengefasst. In einem zweiten Teil dieser Arbeit wird untersucht, auf welchem Wege mit der in MPI verfügbaren Funktionalität auch die Koppelrandkommunikation mit einem einheitlichen und effizienten Verfahren durchgeführt werden kann. Sowohl fuer die Basisimplementierung als auch die MPI-basierte Koppelrandkommunikation wird die Effizienz untersucht und ein Ausblick auf weitere Anwendungsmoeglichkeiten gegeben

Tailoring Boot Camps to Graduate Student Needs

In an effort to strengthen the academic and career preparedness of graduate students at their public land grant university, library faculty organized a one-day boot camp, featuring workshops focused on research and scholarly productivity skills. Organizers of the boot camp recognized that the needs of their graduate students extended beyond the discipline-specific curricula of graduate programs and the content of library orientations and one-shots. The workshop series they developed, informed by input from graduate students, focused on skills and strategies needed throughout the research lifecycle. Graduate student response to the weekend boot camp was overwhelmingly positive, and attendance has grown with each iteration, from 56 attendees at the inaugural boot camp in February 2019 to 117 graduate students at the most recent event in September 2019. The panel presentation will be structured as follows. First, panel members will report on two research studies they conducted to understand the role of the boot camps in addressing the research needs of graduate students. The first study looked at feedback from students who attended the boot camps. Student responses were collected via paper forms and a follow-up Qualtrics survey. Panel presenters coded and analyzed responses to open-ended questions to develop themes that were unique to specific boot camps as well as themes that appeared across multiple boot camps. A second research study, conducted in fall 2019, featured one hour, in-depth interviews of five boot camp participants. The study explored the perspectives of two subgroups of interest: international graduate students (n=3) and non-traditional graduate students (n=2). The interviews were audio-recorded, transcribed, coded, and analyzed to develop themes and patterns in participants’ responses to semi-structured questions about (a) challenges the participants faced in conducting research, (b) skills they believed were needed to address these challenges, and (c) preferred methods or venues for acquiring these skills. In the second part of the presentation, panel members will share strategies for implementing a workshop series based on lessons learned from their research and experiences with their own boot camps. The final part of the presentation will report on steps taken by boot camp organizers to establish partnerships with the library’s Media & Digital Resources Lab and the University’s Graduate School, Graduate Student Council, Office of University Writing, and Center for the Enhancement of Teaching and Learning. These campus partnerships were instrumental in extending the scope and content of the workshops offered

Bridging the Skills Gap: A Boot Camp for Graduate Students

Graduate students have information literacy needs that are distinct from those of undergraduates and faculty. As they prepare for academic and professional careers, graduate students must acquire skills needed to conduct scholarly research; organize and work with information sources; and effectively communicate research findings. These competencies are often not addressed by the curricular content of their graduate programs. To help bridge this gap, library faculty at a public land grant university organized a one-day research skills boot camp. The boot camp’s workshops include sessions on locating scholarly sources, writing literature reviews, organizing citations, managing data, creating engaging presentations, and increasing scholarly impact. Student response to the weekend boot camp has been overwhelmingly positive, with 550 students attending six boot camps during 2019-2020. The presenters will share results from two studies they conducted to better understand the research needs of graduate students. The first study examines survey feedback from boot camp participants, and the second analyzes focus group interviews to gain additional insight about two subgroups of interest: international graduate students and non-traditional graduate students. Panel attendees interested in sponsoring a similar event will receive practical tips on event programming and registration, branding and promotion, and assessment. The presenters will also report on successful collaborations with campus partners focused on student success (e.g., graduate school, writing center, and teaching and learning center)

The effects of experimentally obtained electron correlation and polarization on electron densities and exchange-correlation potentials

In X-ray constrained wavefunction (XCW) fitting, external information, such as electron correlation and polarization, is included into a single-determinantal isolated-molecule wavefunction. In a first step, we show that the extraction of these two physical effects by XCW fitting is complete and accurate by comparing to theoretical reference calculations. In a second step, we show that fitting to data from single-crystal x-ray diffraction measurements provides the same results qualitatively and how the physical effects can be separated, although always inherently convolved in the experiment. We further demonstrate that exchange-correlation potentials are systematically affected by XCW fitting in a physically meaningful way, which could be exploited for method development in quantum chemistry, subject to some remaining challenges that we also outline

Accurate H-atom parameters for the two polymorphs of L-histidine at 5, 105 and 295 K

The crystal structure of the monoclinic polymorph of the primary amino acid l-histidine has been determined for the first time by single-crystal neutron diffraction, while that of the orthorhombic polymorph has been reinvestigated with an untwinned crystal, improving the experimental precision and accuracy. For each polymorph, neutron diffraction data were collected at 5, 105 and 295 K. Single-crystal X-ray diffraction experiments were also performed at the same temperatures. The two polymorphs, whose crystal packing is interpreted by intermolecular interaction energies calculated using the Pixel method, show differences in the energy and geometry of the hydrogen bond formed along the c direction. Taking advantage of the X-ray diffraction data collected at 5 K, the precision and accuracy of the new Hirshfeld atom refinement method implemented in NoSpherA2 were probed choosing various settings of the functionals and basis sets, together with the use of explicit clusters of molecules and enhanced rigid-body restraints for H atoms. Equivalent atomic coordinates and anisotropic displacement parameters were compared and found to agree well with those obtained from the corresponding neutron structural models

Covalency and ionicity do not oppose each other : relationship between Si-O bond character and basicity of siloxanes

Covalency and ionicity are orthogonal rather than antipodal concepts. We demonstrate for the case of siloxane systems [R3Si-(O-SiR2)(n)-O-SiR3] that both covalency and ionicity of the Si-O bonds impact on the basicity of the Si-O-Si linkage. The relationship between the siloxane basicity and the Si-O bond character has been under debate since previous studies have presented conflicting explanations. It has been shown with natural bond orbital methods that increased hyperconjugative interactions of LP(O)->sigma*(Si-R) type, that is, increased orbital overlap and hence covalency, are responsible for the low siloxane basicity at large Si-O-Si angles. On the other hand, increased ionicity towards larger Si-O-Si angles has been revealed with real-space bonding indicators. To resolve this ostensible contradiction, we perform a complementary bonding analysis, which combines orbital-space, real-space, and bond-index considerations. We analyze the isolated disiloxane molecule H3SiOSiH3 with varying Si-O-Si angles, and n-membered cyclic siloxane systems Si2H4O(CH2)(n-3). All methods from quite different realms show that both covalent and ionic interactions increase simultaneously towards larger Si-O-Si angles. In addition, we present highly accurate absolute hydrogen-bond interaction energies of the investigated siloxane molecules with water and silanol as donors. It is found that intermolecular hydrogen bonding is significant at small Si-O-Si angles and weakens as the Si-O-Si angle increases until no stable hydrogen-bond complexes are obtained beyond phi(SiOSi) = 168 degrees, angles typically displayed by minerals or polymers. The maximum hydrogen-bond interaction energy, which is obtained at an angle of 105 degrees, is 11.05 kJ mol(-1) for the siloxane-water complex and 18.40 kJ mol(-1) for the siloxane-silanol complex

Design, implementation and evaluation of a national campaign to distribute nine million free LLINs to children under five years of age in Tanzania.

BACKGROUND\ud \ud After a national voucher scheme in 2004 provided pregnant women and infants with highly subsidized insecticide-treated nets (ITNs), use among children under five years (U5s) in mainland Tanzania increased from 16% in 2004 to 26.2% in 2007. In 2008, the Ministry of Health and Social Welfare planned a catch-up campaign to rapidly and equitably deliver a free long-lasting insecticidal net (LLIN) to every child under five years in Tanzania.\ud \ud METHODS\ud \ud The ITN Cell, a unit within the National Malaria Control Programme (NMCP), coordinated the campaign on behalf of the Ministry of Health and Social Welfare. Government contractors trained and facilitated local government officials to supervise village-level volunteers on a registration of all U5s and the distribution and issuing of LLINs. The registration results formed the basis for the LLIN order and delivery to village level. Caregivers brought their registration coupons to village issuing posts during a three-day period where they received LLINs for their U5s. Household surveys in five districts assessed ITN ownership and use immediately after the campaign.\ud \ud RESULTS\ud \ud Nine donors contributed to the national campaign that purchased and distributed 9.0 million LLINs at an average cost of $7.07 per LLIN, including all campaign-associated activities. The campaign covered all eight zones of mainland Tanzania, the first region being covered separately during an integrated measles immunization/malaria LLIN distribution in August 2008, and was implemented one zone at a time from March 2009 until May 2010. ITN ownership at household level increased from Tanzania's 2008 national average of 45.7% to 63.4%, with significant regional variations. ITN use among U5s increased from 28.8% to 64.1%, a 2.2-fold increase, with increases ranging from 22.1-38.3% percentage points in different regions.\ud \ud CONCLUSION\ud \ud A national-level LLIN distribution strategy that fully engaged local government authorities helped avoid additional burden on the healthcare system. Distribution costs per net were comparable to other public health interventions. Particularly among rural residents, ITN ownership and use increased significantly for the intended beneficiaries. The upcoming universal LLIN distribution and further behaviour change communication will further improve ITN ownership and use in 2010-2011

Impact of mass distribution of free long-lasting insecticidal nets on childhood malaria morbidity: The Togo National Integrated Child Health Campaign

<p>Abstract</p> <p>Background</p> <p>An evaluation of the short-term impact on childhood malaria morbidity of mass distribution of free long-lasting insecticidal nets (LLINs) to households with children aged 9-59 months as part of the Togo National Integrated Child Health Campaign.</p> <p>Methods</p> <p>The prevalence of anaemia and malaria in children aged zero to 59 months was measured during two cross-sectional household cluster-sample surveys conducted during the peak malaria transmission, three months before (Sept 2004, n = 2521) and nine months after the campaign (Sept 2005, n = 2813) in three districts representative of Togo's three epidemiological malaria transmission regions: southern tropical coastal plains (Yoto), central fertile highlands (Ogou) and northern semi-arid savannah (Tone).</p> <p>Results</p> <p>In households with children <5 years of age, insecticide-treated net (ITN) ownership increased from <1% to >65% in all 3 districts. Reported ITN use by children during the previous night was 35.9%, 43.8% and 80.6% in Yoto, Ogou and Tone, respectively. Rainfall patterns were comparable in both years. The overall prevalence of moderate to severe anaemia (Hb < 8.0 g/dL) was reduced by 28% (prevalence ratio [PR] 0.72, 95% CI 0.62-0.84) and mean haemoglobin was increased by 0.35 g/dL (95% CI 0.25-0.45).</p> <p>The effect was predominantly seen in children aged 18-59 months and in the two southern districts: PR (95% CI) for moderate to severe anaemia and clinical malaria: Yoto 0.62 (0.44-0.88) and 0.49 (0.35-0.75); Ogou 0.54 (0.37-0.79) and 0.85 (0.57-1.27), respectively. Similar reductions occurred in children <18 months in Ogou, but not in Yoto. No effect was seen in the semi-arid northern district despite a high malaria burden and ITN coverage.</p> <p>Conclusions</p> <p>A marked reduction in childhood malaria associated morbidity was observed in the year following mass distribution of free LLINs in two of the three districts in Togo. Sub-national level impact evaluations will contribute to a better understanding of the impact of expanding national malaria control efforts.</p

Analysing and Recommending Options for Maintaining Universal Coverage with Long-Lasting Insecticidal Nets: The Case of Tanzania in 2011.

Tanzania achieved universal coverage with long-lasting insecticidal nets (LLINs) in October 2011, after three years of free mass net distribution campaigns and is now faced with the challenge of maintaining high coverage as nets wear out and the population grows. A process of exploring options for a continuous or "Keep-Up" distribution system was initiated in early 2011. This paper presents for the first time a comprehensive national process to review the major considerations, findings and recommendations for the implementation of a new strategy. Stakeholder meetings and site visits were conducted in five locations in Tanzania to garner stakeholder input on the proposed distribution systems. Coverage levels for LLINs and their decline over time were modelled using NetCALC software, taking realistic net decay rates, current demographic profiles and other relevant parameters into consideration. Costs of the different distribution systems were estimated using local data. LLIN delivery was considered via mass campaigns, Antenatal Care-Expanded Programme on Immunization (ANC/EPI), community-based distribution, schools, the commercial sector and different combinations of the above. Most approaches appeared unlikely to maintain universal coverage when used alone. Mass campaigns, even when combined with a continuation of the Tanzania National Voucher Scheme (TNVS), would produce large temporal fluctuations in coverage levels; over 10 years this strategy would require 63.3 million LLINs and a total cost of $444 million USD. Community mechanisms, while able to deliver the required numbers of LLINs, would require a massive scale-up in monitoring, evaluation and supervision systems to ensure accurate application of identification criteria at the community level. School-based approaches combined with the existing TNVS would reach most Tanzanian households and deliver 65.4 million LLINs over 10 years at a total cost of$449 million USD and ensure continuous coverage. The cost of each strategy was largely driven by the number of LLINs delivered. The most cost-efficient strategy to maintain universal coverage is one that best optimizes the numbers of LLINs needed over time. A school-based approach using vouchers targeting all students in Standards 1, 3, 5, 7 and Forms 1 and 2 in combination with the TNVS appears to meet best the criteria of effectiveness, equity and efficiency