Communication system features dual mode range acquisition plus time delay measurement

Communication system combines range acquisition system and time measurement system for tracking high velocity aircraft and spacecraft. The range acquisition system uses a pseudonoise code to determine range and the time measurement system reduces uncontrolled phase variations in the demodulated signal

Without a Map: An Examination of District Leadership During the COVID-19 Crisis

Achieving coherence and coordination in a complex system like a school district is complicated by the nested layers of the organization. This structure allows for teachers in classrooms and schools in a district to operate autonomously, as their organizational layers insulate those in the center from external demands and mandates. The COVID-19 pandemic represented an external demand that led district leaders to implement a series of situational reforms that affected nearly every aspect of the educational organization. This qualitative study examines how the experiences and decision-making processes of district, school, and teacher leaders from a single district in Maine during the COVID-19 pandemic contributed to the district’s coordination and coherence throughout the crisis. Key findings demonstrate that while district leaders acted to establish a decision-making process that centralized decisions, aligned policies, and allocated resources to meet the evolving demands of delivering education during a pandemic, there were factors that acted to facilitate or inhibit the effectiveness of these actions. The most consequential factor related to district coherence was the presence of relational trust throughout the system, as it enhanced communication and collaboration, which contributed to broad diffusions of knowledge across the system. When relational trust was high, members also tolerated uncertainty and adopted changes more readily. The changing conditions and novelty of decisions confronting educational leaders also led to increased networking within the district and across districts in the region. This collaboration led to greater homogeneity and decreased school-based autonomy

Flexible high-voltage supply for experimental electron microscope

Scanning microscope uses a field-emission tip for the electron source, an electron gun that simultaneously accelerates and focuses electrons from the source, and one auxiliary lens to produce a final probe size at the specimen on the order of angstroms

The use of molecular markers for pyramiding resistance genes in grapevine breeding

The practical application of pyramiding resistance genes by the use of molecular markers was investigated in a F1 progeny derived from the cross of VHR 3082-1-42 x ‘Regent’. VHR 3082-1-42 is a cross between Muscadinia rotundifolia x Vitis vinifera, backcrossed another four times with V. vinifera (PAUQUET et al. 2001). It carries the Run1-gene which causes resistance to powdery mildew and the Rpv1-gene which is related to resistance against downy mildew. Both genes were introduced from Muscadinia rotundifolia (BOUQUET et al. 2000; WIEDEMANN-MERDINOGLU et al. 2006). ‘Regent’ is a new cultivar with quantitative resistance against downy and powdery mildew (EIBACH and TÖPFER 2003) released in Germany in 1996 for commercial use. 119 individuals of the F1 progeny were screened with a molecular marker for the Run1-gene (DONALD et al. 2002), with two SSR-markers for the Rpv1-gene (WIEDEMANN-MERDINOGLU et al. 2006) and with several markers from ‘Regent’ that showed good correlation to powdery and downy mildew resistance (ZYPRIAN et al. 2002, SALAKHUTDINOV et al. 2003, AKKURT 2004, FISCHER et al. 2004, AKKURT et al. 2007). Phenotypic evaluation for downy mildew resistance was done by artificial inoculation of leaf discs, and for powdery mildew by natural infection in a greenhouse. Comparison of the phenotypic data with the results of the molecular marker analyses showed a clear correlation between the degree of resistance and the presence of the resistance related alleles. According to the phenotypic data, 20 genotypes of the offspring were free of powdery and downy mildew infections. Based on a marker-assisted evaluation, out of these 20 genotypes a subset of four carried all the resistance related alleles for powdery and downy mildew indicating that resistance genes from both parents were effectively combined.

Powdery mildew responsive genes of resistant grapevine cultivar 'Regent'

The ascomycete Erysiphe necator causes powdery mildew disease of grapevine, a disastrous infection which is commonly defeated with multiple fungicide applications in viticulture. Breeding for natural resistance of quality grapes (Vitis vinifera) is thus a major aim of current efforts. The cultivar 'Regent' is resistant to powdery mildew due to an introgression from an American Vitis sp. resistance donor. To identify key regulatory elements in defense responses of 'Regent' we performed transcript analyses after challenging with E. necator inoculation in comparison with a susceptible grapevine. A set of genes selected from preliminary microarray hybridization results were investigated by RT-qPCR. The data indicate an important role of transcription factors MYB15, WRKY75, WRKY33, WRKY7, ethylene responsive transcription factors ERF2 and ERF5 as well as a CZF1/ZFAR transcripton factor in regulating the early defense when the fungus starts the interaction with its host by the formation of haustoria

The in-flight calibration of the Hubble Space Telescope fine guidance sensors, 2 (a success story)

The Hubble Space Telescope's fine guidance sensors (FGS's) are unique in the performance levels being attempted; spacecraft control and astrometric research with accuracies better than 3 milli-arcseconds (mas) are the ultimate goals. This paper presents a review of the in-flight calibration of the sensors, describing both the algorithms used and the results achieved to date. The work was done primarily in support of engineering operations related to spacecraft pointing and control and secondarily in support of the astrometric science calibration effort led by the Space Telescope Astrometry Team. Calibration items of principal interest are distortion, sensor magnification, and relative alignment. An initial in-flight calibration of the FGS's was performed in December 1990; this calibration has been used operationally over the past few years. Followup work demonstrated that significant, unexpected temporal variations in the calibration parameters are occurring; provided good characterization of the variation; and set the stage for a distortion calibration designed to achieve the full design accuracy for one of the FGS's. This full distortion calibration, using data acquired in January 1993, resulted in a solution having single-axis residuals with a standard deviation of 2.5 mas. Scale and alignment calibration results for all of the FGS's have been achieved commensurate with the best ground-based astrometric catalogs (root-mean-square error approximately 25 mas). A calibration monitoring program has been established to allow regular updates of the calibration parameters as needed

NÊNGUA KAINDA E DONA IARA: SÁBIAS, PODEROSAS MULHERES

This work comprises the analysis of the characters Nêngua Kainda, from the composition Ponciá Vicêncio (2003) by Conceição Evaristo, and the character Dona Iara, from the short story O mistério da Vila published in the book O Sol na Cabeça (2018) by Geovani Martins. These both female characters traverse the space and symbolism of ancestry, religion, spirituality and mysticism, holding differences regarding esteem and prejudice. In Conceição Evaristo’s story, Nêngua Kainda appears as a wise and old woman, revered by theis peers in her wisdom and healing power of hers herbal concoctions. Dona Iara, on her turn, inhabit a contemporanies space and time where the african matrix religion loses space for the christian cults, which putts the character in the ambiguous place of who is target of respect and fear, of reverence and prejudice. Guiding analysis and discussion, are Antonio Candido (2014) and Dalcastagnè (2015).Este trabalho analisa a personagem Nêngua Kainda, da obra Ponciá Vicêncio (2003), de Conceição Evaristo, e a personagem dona Iara, do conto “O mistério da Vila”, publicado no livro O Sol na Cabeça (2018), de Geovani Martins. Ambas personagens femininas transitam pelo espaço e simbolismo da ancestralidade, religião, espiritualidade e misticismo, guardando diferenças entre si no que tange à valorização e preconceito. Na novela de Conceição Evaristo, Nêngua Kainda aparece como uma velha e sábia mulher, reverenciada pelos seus pares em sua sabedoria e poder de cura de suas garrafadas. Dona Iara, por sua vez, ocupa um espaço e tempo contemporâneos nos quais a religião de matriz africana perde lugar para cultos cristãos, o que coloca a personagem no ambíguo lugar de quem é alvo de respeito e medo, de reverência e preconceito. Subsidiando a análise e a discussão, estão Antonio Candido (2014), Dalcastagnè (2015)