1,357,283 research outputs found
Data Hammers et al.
No full textData used in Hammers et al. Breeders the receive help age more slowly in a cooperatively breeding bird. Nature Communications
Data Hammers et al.
No full textData used in Hammers et al. Breeders the receive help age more slowly in a cooperatively breeding bird. Nature Communications
Mary Jean Hammers
No full textMary Jean Hammers died peacefully in Palo Alto after a long battle with Parkinson''s disease. She was 90 years old. She was born Mary Jean Fields in Tipton, Iowa, in 1924. She was one of nine children -- the oldest daughter, but the smallest one in her large family. At her peak, Mary Jean stood only 5 feet tall, but her life was proof that small can be mighty. She left Tipton in 1943, at age 18, moving alone to California to create a life for herself. And that she did. Mary Jean worked for several years at the San Francisco Examiner, and later at the San Jose Mercury News. In 1947 she married Rene Machette, and they settled in San Jose where they had two children, Michael and Michelle. After Rene's death, Mary Jean married Charles zGusy Hammers and had a third child, Chuck. Gus and Mary Jean moved to Salinas where the children were raised and where Mary Jean was the business office manager of the Salinas Valley Memorial Hospital. After retiring, Mary Jean moved to Palo Alto. Mary Jean was a plainspoken and practical woman. She was kind, fiercely independent, fond of watching football and baseball, and listening to Neil Diamond. She was good with numbers, great at crosswords, and she read the newspaper cover to cover right up until the end. Mary Jean could slay you with a one-liner, but also laugh at herself. She took greatest joy in her family. Mary Jean is survived by five of her eight siblings, her son, Michael Machette (Nancy) daughter, Michelle Rapp (Roxy) son, Chuck Hammers (Mary) and seven grandchildren, all of whom will miss her dearly
Evaluation of atlas-based segmentation of hippocampi in healthy humans
No full textIntroduction and aim: Region of interest (ROI)-based functional magnetic resonance imaging (fMRI) data analysis relies on extracting signals from a specific area which is presumed to be involved in the brain activity being studied. The hippocampus is of interest in many functional connectivity studies for example in epilepsy as it plays an important role in epileptogenesis. In this context, ROI may be defined using different techniques. Our study aims at evaluating the spatial correspondence of hippocampal ROIs obtained using three brain atlases with hippocampal ROI obtained using an automatic segmentation algorithm dedicated to the hippocampus.
Material and methods: High-resolution volumetric T1-weighted MR images of 18 healthy volunteers (five females) were acquired on a 3T scanner. Individual ROIs for both hippocampi of each subject were segmented from the MR images using an automatic hippocampus and amygdala segmentation software called SACHA providing the gold standard ROI for comparison with the atlas-derived results. For each subject, hippocampal ROIs were also obtained using three brain atlases: PickAtlas available as a commonly used software toolbox; automated anatomical labeling (AAL) atlas included as a subset of ROI into PickAtlas toolbox and a frequency-based brain atlas by Hammers et al. The levels of agreement between the SACHA results and those obtained using the atlases were assessed based on quantitative indices measuring volume differences and spatial overlap. The comparison was performed in standard Montreal Neurological Institute space, the registration being obtained with SPM5 (http://www.fil.ion.ucl.ac.uk/spm/).
Results: The mean volumetric error across all subjects was 73% for hippocampal ROIs derived from AAL atlas; 20% in case of ROIs derived from the Hammers atlas and 107% for ROIs derived from PickAtlas. The mean false-positive and false-negative classification rates were 60% and 10% respectively for the AAL atlas; 16% and 32% for the Hammers atlas and 6% and 72% for the PickAtlas.
Conclusion: Though atlas-based ROI definition may be convenient, the resulting ROIs may be poor representations of the hippocampus in some studies critical to under- or oversampling. Performance of the AAL atlas was inferior to that of the Hammers atlas. Hippocampal ROIs derived from PickAtlas are highly significantly smaller, and this results in the worst performance out of three atlases. It is advisable that the defined ROIs should be verified with knowledge of neuroanatomy before using it for further data analysis
Do Chimpanzees Use Weight to Select Hammer Tools?
Full text linkThis study was financially supported by a Japan Society for the Promotion of Science Predoc Grant (http://www.jsps.go.jp/english/e-summer/index.html) to Cornelia Schrauf. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The extent to which tool-using animals take into account relevant task parameters is poorly understood. Nut cracking is one of the most complex forms of tool use, the choice of an adequate hammer being a critical aspect in success. Several properties make a hammer suitable for nut cracking, with weight being a key factor in determining the impact of a strike; in general, the greater the weight the fewer strikes required. This study experimentally investigated whether chimpanzees are able to encode the relevance of weight as a property of hammers to crack open nuts. By presenting chimpanzees with three hammers that differed solely in weight, we assessed their ability to relate the weight of the different tools with their effectiveness and thus select the most effective one(s). Our results show that chimpanzees use weight alone in selecting tools to crack open nuts and that experience clearly affects the subjects' attentiveness to the tool properties that are relevant for the task at hand. Chimpanzees can encode the requirements that a nut-cracking tool should meet (in terms of weight) to be effective.Peer reviewe
Hydraulic Demolition Hammers and Shears
No full textThis bachelor thesis deals with the analysis of hydraulic demolition hammers and shears used as an additional equipment of excavators. Thesis contains functional principle, various kinds of actuations of this hydraulical demolition hammers, their usage in special conditions and choice of suitable tool. Moreover thesis contains the principal of funcion of hydraulical demolition shears. Following part shows the summary of hydraulical hammers and shares of four sellected companies on Czech market. Final part shows the comparision of selected types of hydraulical hammers and shares from chosen manufactures. Comparision is displaied in graphs and used to make a conclusion
The Three Hammers PH, Chiswell Green, Hertfordshire. Archaeological Evaluation (OASIS ID: kdkarcha1-266321)
No full textIn January 2017 KDK Archaeology Ltd undertook an Archaeological Evaluation at land adjoining the Three Hammers Public House, Watford Road, Chiswell Green, Hertfordshire. Two trenches were excavated revealing two large features which may be quarry pits, two small ditches, and a feature of indeterminate function which could be a pit, ditch or tree throw. The only finds were post-medieval ceramics, which were recovered from the pit in Trench 1
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