In this paper we detail a precursor survey of this region with PALFA, which observed a subset of the full region (slightly more restrictive in l and |b| lap 1degrees) and detected 45 pulsars. ...Detections included 1 known millisecond pulsar and 11 previously unknown, long-period pulsars. In the surveyed part of the sky that overlaps with the Parkes Multibeam Pulsar Survey (36degrees lap l lap 50degrees), PALFA is probing deeper than the Parkes survey, with four discoveries in this region. For both Galactic millisecond and normal pulsar populations, we compare the survey's detections with simulations to model these populations and, in particular, to estimate the number of observable pulsars in the Galaxy. These are consistent with previous estimates. Identical estimation techniques predict that 490 super(+160) sub(-115), normal pulsars and 12 super(+70) sub(-5) millisecond pulsars would be detected by the beginning of 2014; at the time, the PALFA survey had detected 283 normal pulsars and 31 millisecond pulsars, respectively.
We present two millisecond pulsar discoveries from the PALFA survey of the Galactic plane with the Arecibo telescope. PSR J1955+2527 is an isolated pulsar with a period of 4.87 ms, and PSR J1949+3106 ...has a period of 13.14 ms and is in a 1.9 day binary system with a massive companion. Their timing solutions, based on 4 years of timing measurements with the Arecibo, Green Bank, Nancay, and Jodrell Bank telescopes, allow precise determination of spin and astrometric parameters, including precise determinations of their proper motions. For PSR J1949+3106, we can clearly detect the Shapiro delay. From this we measure the pulsar mass to be 1.47 super(+43) sub(-0.31) M sub(middot in circle), the companion mass to be 0.85 super(+0.14) sub(-0.11) M sub(middot in circle), and the orbital inclination to be i = 79.9 super(-1.9) sub(+1.6) deg, where uncertainties correspond to + or - 1sigma confidence levels. With continued timing, we expect to also be able to detect the advance of periastron for the J1949+3106 system. This effect, combined with the Shapiro delay, will eventually provide very precise mass measurements for this system and a test of general relativity.
The incorporation of potentially catalytic groups in DNA is of interest for the in vitro selection of novel deoxyribozymes. A series of 10 C5-modified analogues of 2'-deoxyuridine triphosphate have ...been synthesised that possess side chains of differing flexibility and bearing a primary amino or imidazole functionality. For each series of nucleotide analogues differing degrees of flexibility of the C5 side chain was achieved through the use of alkynyl, alkenyl and alkyl moieties. The imidazole function was conjugated to these C5-amino-modified nucleotides using either imidazole 4-acetic acid or imidazole 4-acrylic acid (urocanic acid). The substrate properties of the nucleotides (fully replacing dTTP) with TAQ polymerase during PCR have been investigated in order to evaluate their potential applications for in vitro selection experiments. 5-(3-Aminopropynyl)dUTP and 5-(E-3-aminopropenyl)dUTP and their imidazole 4-acetic acid- and urocanic acid-modified conjugates were found to be substrates. In contrast, C5-amino-modified dUTPs with alkane or Z-alkene linkers and their corresponding conjugates were not substrates. The incorporation of these analogues during PCR has been confirmed by inhibition of restriction enzyme digestion using XBAI and by mass spectrometry of the PCR products.
We report 12 new focal mechanisms from earthquakes in NE and SW Tanzania where the stress regime within the East African rift system is not well constrained. Focal mechanisms for events at the ...intersection of the Lake Tanganyika and Rukwa rifts in SW Tanzania indicate a complicated stress pattern with possible dextral strike‐slip motion on some faults but oblique motion on others (either sinistral on NW striking faults or dextral on NE striking faults). Within the Rukwa rift, focal mechanisms indicate normal dip‐slip motion with NE‐SW opening. In NE Tanzania where the Eastern rift impinges on the margin of the Tanzania Craton, fault motions are consistent with a zone of distributed block faults and sub E‐W extension. All twelve earthquakes likely nucleated within the crust.
The ionic liquid (PYR
14TFSI) has proved to be the key material to make a Li-ion conducting element of a complete electrochromic device, when interposed between transparent film electrodes like WO
3 ...and Li-charged V
2O
5. The key features of this ionic liquid and its mixtures with LiTFSI are the excellent transparency in the visible and NIR optical regions, the good ionic conductivity and the electrochemical compatibility with inorganic Li-intercalation oxide thin film electrodes used in electrochromic devices. The higher optical contrast found during WO
3 colouration with PYR
14TFSI-LiTFSI, compared to that in a conventional non-aqueous electrolyte like PC-LiTFSI, was attributed to the larger inertness of the former one (no decomposition reaction at the lowest electrode potential). This highly conductive ionic liquid has been incorporated into a polymer matrix (P(EO)
10LiTFSI), in order to obtain a transparent solid electrolyte with high Li ion conductivity and good mechanical stability. Finally this solid PYR
14TFSI-P(EO)
10LiTFSI transparent ion conductor was interposed between the same electrodes as above in order to yield a fully solid-state, Li-ion electrochromic device. This new solid electrolyte was able to transfer reversibly a Li ionic charge between 5
mC
cm
−2 and 10
mC
cm
−2 from the lithium storage electrode Li
x
V
2O
5 to the WO
3 electrochromic electrode in less than 100
s at room
T, darkening the device from an initial 80% to a final 30% transmittance (at 650
nm). Such a device has been tested first under various constant current conditions, and later under potentiostatic control using ±2
V steps. The latter method allows not only for a faster response of the electrochromic system, but provides also an easier life stability test of the device, which withstood 2000 cycles with little changes in its optical contrast.
The incorporation of C5-amino-modified 2′-deoxyuridine analogues into DNA have found application in nucleic acid labelling, the stabilization of nucleic acid structures, functionalization of nucleic ...acid aptamers and catalysts, and the investigation of sequence-specific DNA bending. In this study, we describe the physicochemical properties of four different C5-amino-modified 2′-deoxyuridines in which the amino group is tethered to the base via a 3-carbon alkyl, Z- or E-alkenyl or alkynyl linker. Conformational parameters of the nucleosides and their pKa values were deduced using 1H NMR. All of them display the expected anti-conformation of the nucleoside with 2′-endo sugar puckers for the deoxyribose ring. A preference for the cisoid conformation for the Z-alkenyl analogue is found, while the E-alkenyl analogue exists exclusively as its transoid conformation. The pKa values range from 10.0 for the analogue with an aliphatic propyl linker to 8.5 for the propargylamino analogue. The analogues have been used for the synthesis of triple-helix forming oligonucleotides (TFOs) in which they replace thymidine in the natural sequence. Oligonucleotides containing the propargylamino analogue display the highest stability especially at low pH, while those containing analogues with propyl and especially Z-alkenyl linkers are destabilized to a great extent. TFOs containing the analogue with the E-alkenyl linker have stability similar to the unmodified structures. The chemical synthesis of TFOs containing the analogue, 5-(3-hydroxyprop-1-ynyl)-2′-deoxyuridine that possesses a neutral but polar side chain show a remarkable stability, which is higher than that of all TFOs containing the alkylamino or alkenylamino analogues and only slightly lower than that of TFOs containing the propargylamino analogue. Both the hydroxyl and propargylamino substitutions impart enhanced triple-helix stability relative to the analogous sequences containing C5-propynyl-2′-deoxyuridine. Furthermore, a similar dependence of stability on pH is found between TFOs containing the hydroxypropynyl modifications and those containing the propargylamino side chains. This suggests that the major factor responsible for stabilizing such triple helices is due to the presence of the alkyne with an attached electronegative group.
Individuals living with cancer are faced with numerous treatment decisions that encompass both conventional therapies and complementary and alternative medicine (CAM). Although a beginning body of ...research has explored the CAM decision-making process by cancer patients, the social context of these treatment decisions has been largely ignored. As a part of a larger grounded theory research project exploring CAM decision-making processes of cancer patients living in British Columbia, Canada, the purpose of this secondary inquiry was to explore how significant others were involved in patients’ decisions related to CAM. In total, 61 patients with early and advanced-stage breast and prostate cancer and 31 significant others participated in semi-structured interviews. Using constant comparative analysis, four main types of decisional involvement by significant others were identified: creating a safe place for the patient to make a decision, “becoming a team”: collaborative decision-making, moving the patient towards a decision, and making the decision for the patient. Significant others were often found to engage in more than one type of decision involvement as a consequence of several key factors. Within the types of decisional involvement, nine distinct roles in the CAM decision-making process were described by the significant others. The findings of this inquiry extend previous research by highlighting the importance of significant others in cancer patients’ CAM decisions and challenge past conceptualizations of autonomy in treatment decision making.
Private Members Bills (PMBs) should provide an important opportunity for backbench MPs to initiate legislative proposals as well as policy debate, to check the executive, and to respond to issues of ...public interest and concern. In recent decades, however, the number of PMBs receiving Royal Assent has steeply declined. Executive control of the timetable has strangled many, and procedural vulnerability has thwarted others, including many that enjoyed broad parliamentary support and commanded public interest. Despite many recent reforms in other areas of the legislative process, the executive and key parliamentary committees have proven impervious to calls for reform of the PMB process. But there are signs that this may be about to change in light of the parliamentary expenses scandal and the renewed interest in the role and function of MPs and the issue of trust and confidence in parliamentarians that this crisis has generated. This article outlines the current procedural problems with the system, explores what the benefits of an effective PMBs system are, analyses what the options for reform might be and how in light of changing political circumstances at Westminster, we might be on the cusp of much needed and potentially far reaching reform in this area.
We present the discovery and phase-coherent timing of four highly dispersed millisecond pulsars (MSPs) from the Arecibo PALFA Galactic plane survey: PSRs J1844+0115, J1850+0124, J1900+0308, and ...J1944+2236. Three of the four pulsars are in binary systems with low-mass companions, which are most likely white dwarfs, and which have orbital periods on the order of days. The fourth pulsar is isolated. All four pulsars have large dispersion measures (DM > 100 pc cm super(-3)), are distant (gap3.4 kpc), faint at 1.4 GHz (lap0.2 mJy), and are fully recycled (with spin periods P between 3.5 and 4.9 ms). The three binaries also have very small orbital eccentricities, as expected for tidally circularized, fully recycled systems with low-mass companions. These four pulsars have DM/P ratios that are among the highest values for field MSPs in the Galaxy. These discoveries bring the total number of confirmed MSPs from the PALFA survey to 15. The discovery of these MSPs illustrates the power of PALFA for finding weak, distant MSPs at low-Galactic latitudes. This is important for accurate estimates of the Galactic MSP population and for the number of MSPs that the Square Kilometer Array can be expected to detect.
A stable i: The i‐motif is a unique, four‐stranded DNA structure associated with cytosine‐rich sequences at the ends of human chromosomes. This is the first report of an i‐motif stabilized by a ...deoxycytidine analogue and demonstrates the importance of the sugar conformation in the i‐motif structure.
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