The Reactions of Muskoxen to Snowmobile Harassment

Twenty-one harassment trials on 14 muskox herds were conducted in April and May 1982 on eastern Melville Island, N.W.T. Each trial consisted of a slow approach directly toward the herd on a snowmobile. The snowmobile, returned along its approach path as soon as 50% of the herd was alerted. Distance at which the first animal reacted (IRD) averaged 345.0 m(range 162-650 m) and the distance from the herd at closest approach (CAD) averaged 267.2 m(range 87-645 m). IRD was positively correlated with wind speed. No correlation between CAD and any of the measured variables was found. Maximum reaction level of the herd was positively correlated with herd size (rs = 0.488, P<0.05). No significant differences in IRD or CAD were found between or among classes of discrete variables such as topography and wind direction, but sample sizes were small. Adult female muskoxen reacted first more frequently than expected (P<0.02). Two herds were approached repeatedly (one six times and one three times) to assess habituation. Results were inconclusive. IRD for the herd that was approached three times decreased progressively. IRD for a herd approached six times was variable but shortest on the sixth approach and the reaction level of the herd also was low on the sixth approach..Key words: muskoxen, harassment, snowmobile, Melville Island, N.W.T.Mots clés: boeuf musqué, harcèlement, motoneige, île Melville, T.N.-O

Influence of association state and DNA binding on the O2-reactivity of [4Fe-4S] fumarate and nitrate reduction (FNR) regulator

The fumarate and nitrate reduction (FNR) regulator is the master switch for the transition between anaerobic and aerobic respiration in Escherichia coli. Reaction of dimeric [4Fe-4S] FNR with O2 results in conversion of the cluster into a [2Fe-2S] form, via a [3Fe-4S] intermediate, leading to the loss of DNA binding through dissociation of the dimer into monomers. In the present paper, we report studies of two previously identified variants of FNR, D154A and I151A, in which the form of the cluster is decoupled from the association state. In vivo studies of permanently dimeric D154A FNR show that DNA binding does not affect the rate of cluster incorporation into the apoprotein or the rate of O2-mediated cluster loss. In vitro studies show that O2-mediated cluster conversion for D154A and the permanent monomer I151A FNR is the same as in wild-type FNR, but with altered kinetics. Decoupling leads to an increase in the rate of the [3Fe-4S]1+ into [2Fe-2S]2+ conversion step, consistent with the suggestion that this step drives association state changes in the wild-type protein. We have also shown that DNA-bound FNR reacts more rapidly with O2 than FNR free in solution, implying that transcriptionally active FNR is the preferred target for reaction with O2

The Self-Dual String and Anomalies in the M5-brane

We study the anomalies of a charge $Q_2$ self-dual string solution in the Coulomb branch of $Q_5$ M5-branes. Cancellation of these anomalies allows us to determine the anomaly of the zero-modes on the self-dual string and their scaling with $Q_2$ and $Q_5$. The dimensional reduction of the five-brane anomalous couplings then lead to certain anomalous couplings for D-branes.Comment: 13 pages, Harvmac, refs adde

Evidence for two protein-lipoylation activities in Escherichia coli

AbstractThe lipoate acyltransferase subunits of the 2-oxo acid dehydrogenase complexes are post-translationally modified with one or more covalently-bound lipoyl cofactors. Two distinct lipoate-protein ligase activities, LPL-A and LPL-B, have been detected in E. coli by their ability to modify purified lipoyl apo-domains of the bacterial pyruvate dehydrogenase complex. Both enzymes require ATP and Mg2+, use L-lipoate, 8-methyllipoate, lipoyl adenylate and octanoyl adenylate as substrates, and both activate lipoyl-deficient pyruvate dehydrogenase complexes. In contrast, only LPL-B uses D-lipoate and octanoate and there are differences in the metal-ion and phosphate requirements. It is suggested that LPL-B may be responsible for the octanoylation of lipoyl domains observed previously under lipoate-deficient conditions

I-Brane Inflow and Anomalous Couplings on D-Branes

We show that the anomalous couplings of $D$-brane gauge and gravitational fields to Ramond-Ramond tensor potentials can be deduced by a simple anomaly inflow argument applied to intersecting $D$-branes and use this to determine the eight-form gravitational coupling.Comment: 8 pages, harvmac, no figure

Nudibranch Range Shifts associated with the 2014 Warm Anomaly in the Northeast Pacific

Abstract.—The Northeast Pacific Ocean was anomalously warm in 2014, despite ENSO-neutral conditions in the tropical Pacific. We documented northern range shifts associated with this anomaly for 30 species of nudibranchs and other shallow-water, benthic heterobranch gastropods from southern California to southern Oregon. Nine of these (Placida cremoniana, Trapania velox, Doriopsilla fulva, Janolus anulatus, J. barbarensis, Flabellina cooperi, Anteaeolidiella chromosoma, A. oliviae, and Noumeaella rubrofasciata) were recorded from new northernmost localities, while the remainder were found at or near northern range limits established mainly during past El Niño events. All 30 species have planktotrophic larval development, and six were observed spawning at northern localities, increasing the likelihood that their ranges will continue to shift poleward as the strong 2015-16 El Niño develops. Notable among these was Okenia rosacea, usually found south of San Francisco and last observed in Oregon as a single specimen found during the 1997-98 El Niño. In 2015 this bright pink nudibranch reached high densities and was observed spawning throughout northern California and into southern Oregon. Okenia rosacea is therefore poised to exploit abundant prey resources previously out of its reach in northern Oregon and Washington. Our results not only demonstrate a striking biological response to the 2014 warm anomaly in the North Pacific Ocean, but also support early physical indications of a larger regional climate shift, one reinforced by long-term global warming. Combined with historical data, these results highlight how shallow-water nudibranchs, with their planktotrophic larvae, short life cycles, conspicuous coloration, and accessibility are excellent biological indicators of ocean climate in the region

Primer Extension Capture: Targeted Sequence Retrieval from Heavily Degraded DNA Sources

We present a method of targeted DNA sequence retrieval from DNA sources which are heavily degraded and contaminated with microbial DNA, as is typical of ancient bones. The method greatly reduces sample destruction and sequencing demands relative to direct PCR or shotgun sequencing approaches. We used this method to reconstruct the complete mitochondrial DNA (mtDNA) genomes of five Neandertals from across their geographic range. The mtDNA genetic diversity of the late Neandertals was approximately three times lower than that of contemporary modern humans. Together with analyses of mtDNA protein evolution, these data suggest that the long-term effective population size of Neandertals was smaller than that of modern humans and extant great apes

Development of the ATAQ-IPF: a tool to assess quality of life in IPF

<p>Abstract</p> <p>Background</p> <p>There is no disease-specific instrument to assess health-related quality of life (HRQL) in patients with idiopathic pulmonary fibrosis (IPF).</p> <p>Methods</p> <p>Patients' perspectives were collected to develop domains and items for an IPF-specific HRQL instrument. We used item variance and Rasch analysis to construct the ATAQ-IPF (A Tool to Assess Quality of life in IPF).</p> <p>Results</p> <p>The ATAQ-IPF version 1 is composed of 74 items comprising 13 domains. All items fit the Rasch model. Domains and the total instrument possess acceptable psychometric characteristics for a multidimensional questionnaire. The pattern of correlations between ATAQ-IPF scores and physiologic variables known to be important in IPF, along with significant differences in ATAQ-IPF scores between subjects using versus those not using supplemental oxygen, support its validity.</p> <p>Conclusions</p> <p>Patient-centered and careful statistical methodologies were used to construct the ATAQ-IPF version 1, an IPF-specific HRQL instrument. Simple summation scoring is used to derive individual domain scores as well as a total score. Results support the validity of the ATAQ-IPF, and future studies will build on that validity.</p

Shocked Molecular Gas in the Supernova Remnant HB 21

We report the discovery of the shocked molecular gas in the supernova remnant HB 21. We derive the physical parameters of the shocked gas from CO J=1-0 and J=2-1 line observations. We discuss the correlation of the shocked molecular gas with the previously detected, shocked atomic gas and the associated infrared emission.Comment: 24 pages, 10 figures, To appear in the ApJ, scheduled for the April 10, 2001 issue (v551