Aspects of G-Complete reducibility

Let G be a connected reductive algebraic group, and ? a Frobenius morphism of G. Corresponding to the notion of G complete reducibility, due to J.-P. Serre, we introduce a new notion of (G; ?)-complete reducibility. We show that a ?-stable subgroup of G is (G; ?)-completely reducible if and only if it is G-completely reducible. We also strengthen this result in one direction to show that if H is a ?-stable non G-completely reducible subgroup of G, then it is contained in a proper ?-stable parabolic subgroup P of G, and in no Levi subgroup of P. We go on to introduce another new notion, that of G?- complete reducibility for subgroups of G?. We show that a subgroup of G? is G? completely reducible if and only if it is (G; ?)-completely reducible. Finally, we introduce the notion of strong ?-reductivity in G for ?-stable subgroups of G, and show that this is an analogue to the notion of strong reductivity in G in the setting of ?-stability. We discuss a notion of G-complete reducibility for Lie subalgebras of Lie(G), which was introduced by McNinch. We show that if H is a subgroup of G that is contained in C (S), where S is a maximal torus of CG(Lie(H)), then H is G-completely reducible if and only if Lie(H) is G-completely reducible. We give criteria for a Lie subalgebra of Lie(G) to be G-completely reducible. For example, an ideal in Lie(G) is G-completely reducible if it isinvariant under the adjoint action of G

History of Volusia County, Florida

Chp. 1 Early history, indians and antiquities pg.7 Chp. 2 French and Spanish regimes (1564-1763) pg. 13 Chp. 3 English regime and Minorcan settlement at New Smyrna (1763-1784) pg. 19 Chp. 4 English regime and settlemenet at New Smyrna (1763-1784)--(Continued) pg. 24 Chp. 5 Return of the Spanish (1783-1790) pg. 30 Chp. 6 Spanish land grants (1790-1821) pg. 34 Chp. 7 Change of flags (1821-1824) pg. 39 Chp. 8 Mosquito County (1824-1835) pg. 45 Chp. 9 Seminole War (1835-1842) pg. 51 Chp. 10 Seminole War (1835-1842)--(Continued) pg. 57 Chp. 11 Effort to change Mosquito to Lead Read County (1842-1844) pg. 62 Chp. 12 Orange County (1845-1854) pg. 71 Chp. 13 Volusia (1845-1854) pg. 78 Chp. 14 Early days in the county of Volusia and the Civil War (1855-1856) pg. 85 Chp. 15 After the war (1865-1870) pg. 93 Chp. 16 Founding of Daytona and Ormond (1870-1880) pg. 101 Chp. 17 DeLand (1873-1890) pg. 111 Chp. 18 Settlements at Orange City, Lake Helen, DeLeon Springs and on the East Coast pg. 118 Chp. 19 Coming of the railroads (1881-1891) Chp. 20 Seabreeze, Daytona Beach and New Smyrna (1887-1907) pg. 137 Chp. 21 Political, educational and social development (1870-1927) pg. 142 Volusia of our own times (1898-1927) pg. 15

Xenopus Drf1, a Regulator of Cdc7, Displays Checkpoint-dependent Accumulation on Chromatin during an S-phase Arrest

We have cloned a Xenopus Dbf4-related factor named Drf1 and characterized this protein by using Xenopus egg extracts. Drf1 forms an active complex with the kinase Cdc7. However, most of the Cdc7 in egg extracts is not associated with Drf1, which raises the possibility that some or all of the remaining Cdc7 is bound to another Dbf4-related protein. Immunodepletion of Drf1 does not prevent DNA replication in egg extracts. Consistent with this observation, Cdc45 can still associate with chromatin in Drf1-depleted extracts, albeit at significantly reduced levels. Nonetheless, Drf1 displays highly regulated binding to replicating chromatin. Treatment of egg extracts with aphidicolin results in a substantial accumulation of Drf1 on chromatin. This accumulation is blocked by addition of caffeine and by immunodepletion of either ATR or Claspin. These observations suggest that the increased binding of Drf1 to aphidicolin-treated chromatin is an active process that is mediated by a caffeine-sensitive checkpoint pathway containing ATR and Claspin. Abrogation of this pathway also leads to a large increase in the binding of Cdc45 to chromatin. This increase is substantially reduced in the absence of Drf1, which suggests that regulation of Drf1 might be involved in the suppression of Cdc45 loading during replication arrest. We also provide evidence that elimination of this checkpoint causes resumed initiation of DNA replication in both Xenopus tissue culture cells and egg extracts. Taken together, these observations argue that Drf1 is regulated by an intra-S-phase checkpoint mechanism that down-regulates the loading of Cdc45 onto chromatin containing DNA replication blocks

Roles of replication fork-interacting and Chk1-activating domains from claspin in a DNA replication checkpoint response

Claspin is essential for the ATR-dependent activation of Chk1 in Xenopus egg extracts containing incompletely replicated DNA. Claspin associates with replication forks upon origin unwinding. We show that Claspin contains a replication fork-interacting domain (RFID, residues 265–605) that associates with Cdc45, DNA polymerase ε, replication protein A, and two replication factor C complexes on chromatin. The RFID contains two basic patches (BP1 and BP2) at amino acids 265–331 and 470–600, respectively. Deletion of either BP1 or BP2 compromises optimal binding of Claspin to chromatin. Absence of BP1 has no effect on the ability of Claspin to mediate activation of Chk1. By contrast, removal of BP2 causes a large reduction in the Chk1-activating potency of Claspin. We also find that Claspin contains a small Chk1-activating domain (residues 776–905) that does not bind stably to chromatin, but it is fully effective at high concentrations for mediating activation of Chk1. These results indicate that stable retention of Claspin on chromatin is not necessary for activation of Chk1. Instead, our findings suggest that only transient interaction of Claspin with replication forks potentiates its Chk1-activating function. Another implication of this work is that stable binding of Claspin to chromatin may play a role in other functions besides the activation of Chk1

Learning by volunteer computing, thinking and gaming: What and how are volunteers learning by participating in Virtual Citizen Science?

Citizen Science (CS) refers to a form of research collaboration that engages volunteers without formal scientific training in contributing to empirical scientific projects. Virtual Citizen Science (VCS) projects engage participants in online tasks. VCS has demonstrated its usefulness for research, however little is known about its learning potential for volunteers. This paper reports on research exploring the learning outcomes and processes in VCS. In order to identify different kinds of learning, 32 exploratory interviews of volunteers were conducted in three different VCS projects. We found six main learning outcomes related to different participants' activities in the project. Volunteers learn on four dimensions that are directly related to the scope of the VCS project: they learn at the task/game level, acquire pattern recognition skills, on-topic content knowledge, and improve their scientific literacy. Thanks to indirect opportunities of VCS projects, volunteers learn on two additional dimensions: off topic knowledge and skills, and personal development. Activities through which volunteers learn can be categorized in two levels: at a micro (task/game) level that is direct participation to the task, and at a macro level, i.e. use of project documentation, personal research on the Internet, and practicing specific roles in project communities. Both types are influenced by interactions with others in chat or forums. Most learning happens to be informal, unstructured and social. Volunteers do not only learn from others by interacting with scientists and their peers, but also by working for others: they gain knowledge, new status and skills by acting as active participants, moderators, editors, translators, community managers, etc. in a project community. This research highlights these informal and social aspects in adult learning and science education and also stresses the importance for learning through the indirect opportunities provided by the project: the main one being the opportunity to participate and progress in a project community, according to one's tastes and skills

Birth seasonality studies in a large Prader-Willi syndrome cohort.

Prader-Willi syndrome (PWS) is generally due to sporadic paternal deletions of the chromosome 15q11-q13 region followed by maternal disomy 15. Advanced maternal age is more commonly seen in those with maternal disomy 15. Environmental factors (e.g., drug use, occupational chemical exposure, infectious agents, and irradiation) could account for chromosome changes. Previous evidence of differences in male and female gametogenesis could suggest an environmental role in the causation of the paternal 15q11-q13 deletion seen in PWS. Certain occupations such as hydrocarbon-exposing occupations (e.g., landscaping, farming, and painting) and viral exposure (e.g., human coronavirus 229E causing upper respiratory infections in adults with an incorporation site in the human genome at chromosome 15q11) can be seasonal in nature and contribute to chromosome damage. To assess, we reviewed birth seasonality data in a large cohort of individuals with PWS recruited nationally (N = 355) but no significant differences were seen by month between those with the 15q11-q13 deletion compared with maternal disomy 15 when analyzing quarterly seasonal patterns. Although early evidence supported birth seasonality differences in PWS, a larger number of individuals in our recent study using advanced genetic testing methods did not find this observation

Adjuvant Immunotherapy Is Dependent on Inducible Nitric Oxide Synthase

Rodents immunized with complete Freund's adjuvant (CFA) are resistant to subsequent attempts to induce autoimmune disease, while animals immunized with incomplete Freund's adjuvant (IFA) remain susceptible. Mycobacterial extracts can stimulate inducible nitric oxide synthase (NOS2) gene transcription. Robust expression of NOS2 has been linked to suppression of T cell proliferation and alterations in immune responses. Our studies investigated the hypothesis that the immunoprotective effect of CFA before immunization requires functional NOS2. NOS2 gene expression is chronically elevated in lymph nodes and spleens of CFA-immunized mice. Maximal expression of NOS2 after CFA immunization requires the presence of functional type I tumor necrosis factor α receptor (TNFR1) and interferon γ. Groups of nontreated and CFA-preimmunized male C57BL/6J or C57BL/6NOS2−/− mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide 35–55 in CFA to induce experimental allergic encephalomyelitis (EAE). Wild-type C57BL/6J mice were protected from the development of symptoms of EAE, while the NOS2−/− mice failed to be protected. NOS2-dependent effects of CFA included an augmentation of the MOG-specific IgG1 response, a decrease in interleukin 6 production by MOG-reactive lymphocytes, and a marked decrease in mononuclear cell infiltrates in the central nervous system. These studies support the hypothesis that CFA immunization modulates immune responses through a nitric oxide–dependent mechanism

Medication Abortion: A Sample Protocol for Increasing Access During a Pandemic and Beyond

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A review of pursuit and saccadic eye movements and their utility in stroke

The head impulse-nystagmus-test of skew (+ hearing) or HINTS+ exam is a well-established clinical bedside test used in evaluating whether patients with the acute vestibular syndrome have features concerning for a central etiology (e.g., stroke). There are other components of the ocular motor exam that are helpful in the acute setting, including smooth pursuit and saccades. We discuss the anatomy and physiology of the saccade and smooth pursuit pathways from the cortex to the infratentorial region in the context of anterior and posterior circulation strokes in general but with a particular emphasis on distinct vestibular stroke syndromes. For each stroke localization, we review the vascular supply and the expected findings on the HINTS+ exam and correlate this with the expected findings on the smooth pursuit and saccade exams to aid in bedside diagnosis

Cognitive Primitives of Collective Intentions: Linguistic Evidence of Our Mental Ontology

Theories of collective intentions must distinguish genuinely collective intentions from coincidentally harmonized ones. Two apparently equally apt ways of doing so are the ‘neo‐reductionism’ of Bacharach (2006) and Gold and Sugden (2007a) and the ‘non‐reductionism’ of Searle (1990, 1995). Here, we present findings from theoretical linguistics that show that we is not a cognitive primitive, but is composed of notions of I and grouphood. The ramifications of this finding on the structure both of grammatical and lexical systems suggests that an understanding of collective intentionality does not require a primitive we‐intention, but the notion of grouphood implicit in team reasoning, coupled with the individual concept I. This, we argue, supports neo‐reductionism but poses difficulties for non‐reductionism