32 research outputs found
Proceedings of the 22nd annual Central Plains irrigation conference, Kearney, Nebraska, February 24-25, 2010
No full textPresented at the 22nd annual Central Plains irrigation conference on February 24-25, 2010 in Kearney, Nebraska
Bullying Among Mainstream Students in Turkish Schools: Models for Prevention
No full textAbstractA growing body of literature has been focusing bullying and students with disabilities. The main idea of bullying is that students with disabilities are particularly vulnerable to bullying (Hergert, 2004; Hoover & Stenhjem, 2003; PACER Center, 2007). Even though there is a great awareness of bullying in Turkish schools, Turkish education system is in need of an urgent prevention model or models for both normally developing students and those with special needs. The author points out bullying prevention programs and interventions cited in the literature and discusses the concerns related to the credibility of utilizing current bullying prevention programs and interventions with students with disabilities. The author suggests that in order to benefit from any bullying prevention program or intervention for students with disabilities, accommodations or modifications to the programs are required. Otherwise, the efforts of school administrators, staff, and parents may be unsuccessful in attempting to reduce or eliminate the instances of bullying of students with disabilities in schools
Limited irrigation cropping systems for conserving water resources in the Pumpkin Creek Watershed
Get PDFPresented at the 2008 Central Plains irrigation conference on February 19-20 in Greeley, Colorado
Control of daughter centriole formation by the pericentriolar material
Get PDFAuthor Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Cell Biology 10 (2008): 322-328, doi:10.1038/ncb1694.Controlling the number of its centrioles is vital for the cell as supernumerary
centrioles result in multipolar mitosis and genomic instability. Normally, just one
daughter centriole forms on each mature (mother) centriole; however, a mother
centriole can produce multiple daughters within a single cell cycle. The
mechanisms that prevent centriole ‘overduplication’ are poorly understood. Here we
use laser microsurgery to test the hypothesis that attachment of the daughter
centriole to the wall of the mother inhibits formation of additional daughters. We
show that physical removal of the daughter induces reduplication of the mother in Sarrested
cells. Under conditions when multiple daughters simultaneously form on a
single mother, all of these daughters must be removed to induce reduplication.
Intriguingly, the number of daughter centrioles that form during reduplication does
not always match the number of ablated daughter centrioles. We also find that
exaggeration of the pericentriolar material (PCM) via overexpression of the PCM
protein pericentrin in S-arrested CHO cells induces formation of numerous daughter
centrioles. We propose that that the size of the PCM cloud associated with the
mother centriole restricts the number of daughters that can form simultaneously.This work was supported
by grants from the National Institutes of Health (GM GM59363) and the Human Frontiers
Science Program (RGP0064). Construction of our laser microsurgery workstation was
supported in part by a fellowship from Nikon/Marine Biological Laboratory (A.K.)
Proceedings of the 23rd annual Central Plains irrigation conference
Get PDFPresented at Proceedings of the 23rd annual Central Plains irrigation conference held in Burlington, Colorado on February 22-23, 2011
Laser microsurgery in the GFP era : a cell biologist's perspective
Get PDFAuthor Posting. © The Author(s), 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Methods in Cell Biology 82 (2007): 237, 239-266, doi:10.1016/S0091-679X(06)82007-8.Modern biology is based largely on a reductionistic ‘dissection’ approach – most cell
biologists try to determine how complex biological systems work by removing their individual
parts and studying the effects of this removal on the system. A variety of enzymatic and
mechanical methods have been developed to dissect large cell assemblies like tissues and organs.
Further, individual proteins can be inactivated or removed within a cell by genetic manipulations
(e.g., RNAi or gene knockouts). However, there is a growing demand for tools that allow
intracellular manipulations at the level of individual organelles. Laser microsurgery is ideally
suited for this purpose and the popularity of this approach is on the rise among cell biologists. In
this chapter we review some of the applications for laser microsurgery at the subcellular level,
and describe practical requirements for laser microsurgery instrumentation demanded in the
field. We also outline a relatively inexpensive but versatile laser microsurgery workstation that is
being used in our lab. Our major thesis is that the limitations of the technology are no longer at
the level of the laser, microscope or software, but instead only in defining creative questions and
in visualizing the target to be destroyed.Our work is sponsored by
grants from the NIH (GM59363 to AK and GM40198 to CLR) and HFSP (RGP0064 to AK).
Construction of the laser microsurgery workstation was supported in par by Summer Research
Fellowship from Nikon/Marine Biological Laboratory (2003 to AK)
The analysis of slip tendency of major tectonic faults in Germany
Get PDFSeismic hazard during subsurface operations is often related to the reactivation of pre-existing tectonic faults. The analysis of the slip tendency, i.e., the ratio of shear to normal stress acting on the fault plane, allows an assessment of the reactivation potential of faults. We use the total stresses that result from a large-scale 3D geomechanical–numerical model of Germany and adjacent areas to calculate the slip tendency for three 3D fault geometry sets with increasing complexity. This allows us to draw general conclusions about the influence of the fault geometry on the reactivation potential.
In general, the fault reactivation potential is higher in Germany for faults that strike NW–SE and NNE–SSW. Due to the prevailing normal stress regime in the geomechanical–numerical model results, faults dipping at an angle of about 60∘ generally show higher slip tendencies in comparison to steeper or shallower dipping faults. Faults implemented with a straight geometry show higher slip tendencies than those represented with a more complex, uneven geometry. Pore pressure has been assumed to be hydrostatic and has been shown to have a major influence on the calculated slip tendencies. Compared to slip tendency values calculated without pore pressure, the consideration of pore pressure leads to an increase in slip tendency of up to 50 %. The qualitative comparison of the slip tendency with the occurrence of seismic events with moment magnitudes M>3.5 shows areas with an overall good spatial correlation between elevated slip tendencies and seismic activity but also highlights areas where more detailed and diverse fault sets would be beneficial
SpannEnD – a 3D geomechanical model of Germany for the prediction of the recent crustal stress state
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